Process for the manufacture of (2s,3s,4s,5r,6s)-3,4,5-trihydroxy-6-(((4ar,10ar)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2h-pyran-2-carboxylic acid

ABSTRACT

The invention also relates to new intermediates of said process.

FIELD OF THE INVENTION

The present invention relates to a process for manufacturing(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylicacid which is a compound for use in the treatment of neurodegenerativediseases and disorders such as Parkinson's Disease. The invention alsorelates to new intermediates of said process.

BACKGROUND OF THE INVENTION

Parkinson's disease (PD) is a common neurodegenerative disorder thatbecomes increasingly prevalent with age and affects an estimated sevento ten million people worldwide. Parkinson's disease is a multi-faceteddisease characterized by both motor and non-motor symptoms. Motorsymptoms include resting tremor (shaking), bradykinesia/akinesia(slowness and poverty of movements), muscular rigidity, posturalinstability and gait dysfunction; whereas non-motor symptoms includeneuropsychiatric disorders (e.g. depression, psychotic symptoms,anxiety, apathy, mild-cognitive impairment and dementia) as well asautonomic dysfunctions and sleep disturbances (Poewe et al., NatureReview, (2017) vol 3 article 17013: 1-21).

A key hallmark of Parkinson's disease pathophysiology is the loss ofpigmented dopaminergic neurons in the substantia nigra pars compactathat provides dopaminergic innervation to the striatum and other brainareas. Such progressive neurodegeneration leads to the decrease indopamine striatal levels which ultimately results in a series of changesin the basal ganglia circuitry, ultimately ending up in the occurrenceof the four cardinal motor features of Parkinson's disease. The maintarget of dopamine in the striatum consists of medium spiny GABAergicneurons (MSNs) selectively expressing D1 or D2 receptors pendingtopographical projections. GABAergic-MSN projecting to the externalpallidum, also called striato-pallidal ‘indirect pathway’ express D2receptors (MSN-2); whereas GABAergic-MSN projecting to the substantianigra pars reticulata and internal pallidum, also called striato-nigral‘direct pathway’ express D1 receptors (MSN-1). Depletion of dopaminebecause of neuronal loss results in an imbalanced activity of the twopathways, resulting in a marked reduction of thalamic and corticaloutput activities and ultimately motor dysfunctions (Gerfen et al,Science (1990) 250: 1429-32; Delong, (1990) Trends in Neuroscience 13:281-5; Alexander et Crutcher, (1990) Trends in Neuroscience 13: 266-71;and for review Poewe et al., Nature Review (2017) vol. 3 article 17013:1-21).

The most effective therapeutic strategies available to patientssuffering from Parkinson's disease, and aiming at controlling motorsymptoms are primarily indirect and direct dopamine agonists. Theclassic and gold standard treatment regimen includes chronic oral intakeof L-3,4-dihydroxy phenylalanine (L-DOPA) which is decarboxylated in thebrain to form dopamine. Other approaches consist in the administrationof dopamine receptor agonists such as apomorphine which acts both on theD1 and D2 receptors subtypes, or pramipexole, ropinirole and otherswhich are predominantly directed towards D2 receptors subtypes. Optimalmotor relief is obtained with use of both L-DOPA and apomorphine due totheir activation of both D1 and D2 receptor subtypes and holisticre-equilibrium of the indirect-direct pathways (i.e. while D2 agonistsonly reverse the indirect pathway dysfunction).

L-DOPA and apomorphine with the structures depicted below are currentlythe most efficacious PD drugs in clinical use.

L-DOPA is a prodrug of dopamine and remains the most efficacious drug inthe treatment of motor Parkinson's disease. However, after several yearsof treatment (i.e. honeymoon period), complications arise due theinherent progression of the disease (i.e. sustained loss of dopaminergicneurons) as well as poor pharmacokinetic (PK) profile of L-DOPA. Thosecomplications include 1) dyskinesia which are abnormal involuntarymovements occurring during the optimal ‘on-time effect’ of the drug; and2) off fluctuations, period during which the L-DOPA positive effectwears off and symptoms re-emerge or worsen (Sprenger and Poewe, CNSDrugs (2013), 27: 259-272). Direct dopamine receptor agonists are ableto activate the dopamine autoreceptors as well as the postsynapticdopamine receptors located on the medium spiny neurons MSN-1 and MSN-2.Apomorphine belongs to a class of dopamine agonists with a1,2-dihydroxybenzene (catechol) moiety. When combined with aphenethylamine motif, catecholamines often possess low or no oralbioavailability as is the case for apomorphine. Apomorphine is usedclinically in PD therapy albeit with a non-oral delivery (typicallyintermittent subcutaneous administration or daytime continuousparenteral infusion via a pump). For apomorphine, animal studies haveshown that transdermal delivery or implants may provide possible formsof administration. However, when the delivery of apomorphine fromimplants was studied in monkeys (Bibbiani et al., Chase ExperimentalNeurology (2005), 192: 73-78) it was found that in most cases theanimals had to be treated with the immunosuppressant dexamethasone toprevent local irritation and other complications following theimplantation surgery. Alternative delivery strategies for apomorphinetherapy in PD such as inhalation and sublingual formulations have beenextensively explored (see e.g. Grosset et al., Acta Neurol Scand.(2013), 128:166-171 and Hauser et al., Movement Disorders (2016), Vol.32 (9): 1367-1372). However, these efforts are yet not in clinical usefor the treatment of PD.

An alternative to the non-oral formulations of the catecholaminesinvolves the use of a prodrug masking the free catechol hydroxyl groupsto enable oral administration. However, a known problem associated withthe development of prodrugs for clinical use is the difficultiesassociated with predicting conversion to the parent compound in humans.

Various ester prodrugs of catecholamines have been reported in theliterature such as enterically coated N-propyl-noraporphine (NPA) andthe mono pivaloyl ester of apomorphine for duodenal delivery (see eg. WO02/100377), and the D1-like agonist adrogolide, a diacetyl prodrug ofA-86929 (Giardina and Williams; CNS Drug Reviews (2001), Vol. 7 (3):305-316). adrogolide undergoes extensive hepatic first-pass metabolismin man after oral dosing and, as a result, has a low oralbioavailability (app. 4%). In PD patients, intravenous (IV) adrogolidehas antiparkinson efficacy comparable to that of L-DOPA (Giardina andWilliams; CNS Drug Reviews (2001), Vol. 7 (3): 305-316).

In addition to the ester prodrugs of catecholamines, an alternativeprodrug approach involves the masking of the two catechol hydroxylgroups as the corresponding methylene-dioxy derivative or di-acetalylderivative, as the acetal derived from other aldehydes thanformaldehyde, or as the ketal derived from various ketones. This prodrugprinciple has been described for example in Campbell et al.,Neuropharmacology (1982); 21(10): 953-961 and in U.S. Pat. No.4,543,256, WO 2009/026934 and WO 2009/026935.

Yet another suggested approach for a catecholamine prodrug is theformation of an enone derivative as suggested in for example WO2001/078713 and in Liu et al. Bioorganic Med. Chem. (2008), 16:3438-3444. For further examples of catecholamine prodrugs see forexample Sozio et al., Exp. Opin. Drug Disc. (2012); 7(5): 385-406.

The compound(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-dioldepicted as compound (I) below is disclosed in WO 2009/026934. Thetrans-isomer was disclosed previously in Liu et al., J. Med. Chem.(2006), 49: 1494-1498 and then in Liu et al., Bioorganic Med. Chem.(2008), 16: 3438-3444 including pharmacological data indicating that thecompound has a low oral bioavailability in rats. The racemate wasdisclosed for the first time in Cannon et al., J. Heterocyclic Chem.(1980); 17: 1633-1636.

Compound (I) is a dopamine receptor agonist with mixed D1 and D2activity. Some prodrug derivatives of compound (I) are known in the art.

Liu et al., J. Med. Chem. (2006), 49: 1494-1498 and Liu et al.,Bioorganic Med. Chem. (2008), 16: 3438-3444 disclose the enonederivative of formula (Ia) depicted below which was shown to beconverted to the active compound (I) in rats.

WO 2009/026934 and WO 2009/026935 disclose two types of prodrugderivatives of compound (I) including a compound with the formula (Ib)below:

The conversion of compound (Ib) to compound (I) in rat and humanhepatocytes has been demonstrated in WO 2010/097092. Furthermore, the invivo pharmacology of the compounds (Ia) and (Ib) as well as the active“parent compound” (1) has been tested in various animal models relevantfor Parkinson's Disease (WO 2010/097092). Both compound (I) andcompounds (Ia) and (Ib) were found to be effective, indicating thatcompounds (Ia) and (Ib) are converted in vivo to compound (I). All threecompounds were reported to have a duration of action that was longerthan observed for L-dopa and apomorphine.

The other prodrug of compound (I) disclosed in WO 2009/026934 and WO2009/026935 is a conventional ester prodrug of the formula (Ic):

Despite the long-standing interest in the field, there is evidentlystill an unmet need as regards developing efficient, well-tolerated andorally active drugs for the treatment of PD. A prodrug derivative of amixed D1/D2 agonist giving a stable PK profile which can providecontinuous dopaminergic stimulation may fulfil such unmet needs.

Consequently, there is also a need for a process for manufacturing ofsuch drugs, particularly processes that are suitable for large scaleproduction and resulting in a high yield of the compound of formula(Id).

SUMMARY OF THE INVENTION

Surprisingly, it has been observed that oral dosing of(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylicacid (compound (Id)) provides a systemic exposure of compound (I) inplasma, suggesting the usefulness of said compound as an orally activeprodrug of compound (I). Examples 9 and 10 herein demonstrate theadvantageous in vitro and in vivo effects of the compound (I) afterdosing of compound (Id).

The present invention relates to a novel process for the manufacture of(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylicacid with the formula (Id) below

from the compound(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-diolwith the formula (I) below

The process involves benzylation of the compound (I) to introduceprotection groups that allows for selective coupling to a glucuconicacid conjugate.

The overall process starting from compound (I) is illustrated in briefin Scheme 1 below.

X is selected from the group consisting of Cl, Br and I.

Y is an alkali metal preferably selected from the group consisting ofLi, Na and K.

In a specific embodiment of the invention, X is Cl.

In a specific embodiment of the invention, Y is K (potassium).

Individual aspects relate to each of the process steps 1), 2), 3), 4)and 5).

Other individual aspects of the invention relate to new intermediates ofthe process. Thus, further aspects of the present invention provide thecompounds (A2), (A3), (A4) and (A5) and salts thereof respectively,which are useful intermediates in the processes for the manufacturing ofthe compound (Id).

The overall process, as well as each individual process step andintermediates as provided by the invention are useful for large scaleproduction of compound (Id) and can be applied without, or whileminimizing, use of column chromatography. Avoidance of columnchromatography is advantageous, since it facilitates large scaleproduction of the compound (Id).

Definitions References to Compounds

References to compound (I), compound (Id), (A2), (A3), (A4) and (A5)include the compounds in solution and solid forms of the compoundsincluding the free substance (zwitter ion) of said compounds, salts ofsaid compounds, such as acid addition salts or base addition salts, andpolymorphic and amorphic forms of compounds of the invention and ofsalts thereof. Furthermore, said compounds and salts thereof maypotentially exist in unsolvated as well as in solvated forms withpharmaceutically acceptable solvents such as water, ethanol and thelike. In an embodiment, the salt of compound (Id) is a pharmaceuticallyacceptable salt.

Sometimes, a specific salt form is indicated for a compound such as forexample (A3-HI) which indicates the HI salt of (A3), or (A5-Y) whichindicates an alkali salt of (A5) such as the potassium salt.

Pharmaceutically Acceptable Salts:

Pharmaceutically acceptable salts in the present context is intended toindicate non-toxic, i.e. physiologically acceptable salts.

The term “pharmaceutically acceptable salts” include pharmaceuticallyacceptable acid addition salts which are salts formed with inorganicand/or organic acids on the nitrogen atom in the parent molecule. Saidacids may be selected from for example hydrochloric acid, hydrobromicacid, phosphoric acid, nitrous acid, sulphuric acid, benzoic acid,citric acid, gluconic acid, lactic acid, maleic acid, succinic acid,tartaric acid, acetic acid, propionic acid, oxalic acid, malonic acid,fumaric acid, glutamic acid, pyroglutamic acid, salicylic acid, gentisicacid, saccharin, and sulfonic acids such as methanesulfonic acid,ethanesulfonic acid, toluenesulfonic acid, naphthalene-2-sulphonic acid,2-hydroxy ethanesulphonic acid and benzenesulfonic acid.

The term pharmaceutically acceptable salts also include pharmaceuticallyacceptable base addition salts which are salts formed with inorganicand/or organic bases on the acidic groups of the compound of formula(Id). Said bases may be selected from for example zink hydroxide, andalkali metal bases, such as sodium hydroxide, lithium hydroxide,potassium hydroxide, and alkaline earth bases, such as calcium hydroxideand magnesium hydroxide, and organic bases, such as choline,diethylamine, trimethylamine and triethylamine.

Additional examples of useful acids and bases to form pharmaceuticallyacceptable salts can be found e.g. in Stahl and Wermuth (Eds) “Handbookof Pharmaceutical salts. Properties, selection, and use”, Wiley-VCH,2008.

Compounds (I), (A2), (A3), (A4), and (A5) may be used as intermediatesfor the manufacture of compound (Id)). Hence, the salt forms of theintermediates are not limited to pharmaceutically acceptable saltsthereof. Nevertheless, pharmaceutically acceptable salts of thecompounds (I), (A2), (A3), (A4), and (A5) can also advantageously beused in the manufacture of compound (Id) and compound (Ib). Hence, in anembodiment of the invention the salt of compound (I), (A2), (A3), (A4),(A5), and compound (Id) is a pharmaceutically acceptable salt.

Prodrug

In the present context, the terms “prodrug” or “prodrug derivative”indicates a compound that, after administration to a living subject,such as a mammal, preferably a human is converted within the body into apharmacologically active moiety. The conversion preferably takes placewithin a mammal, such as in a mouse, rat, dog, minipig, rabbit, monkeyand/or human. In the present context a “prodrug of the compound(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-diol”or “a prodrug of the compound of formula (I)” or “a prodrug of compound(I)” is understood to be a compound that, after administration, isconverted within the body into the compound(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-diol.Said administration may be by any conventional route of administrationof pharmaceutical compositions known in the art, preferably by oraladministration.

In the present context, the terms “parent compound” and “parentmolecule” indicate the pharmacologically active moiety obtained uponconversion of a corresponding prodrug. For example, the “parentcompound” of the compound of formula (Id) is understood to be thecompound of formula (I).

Pharmacokinetic Definitions and Abbreviations

As used herein, a “PK profile” is an abbreviation of “pharmacokineticprofile”. Pharmacokinetic profiles and pharmacokinetic parametersdescribed herein are based on the plasma concentration-time dataobtained for the compound of formula (I) after oral dosing of thecompound of formula (Id), using non-compartmental modelling. AbbreviatedPK parameters are: C_(max) (maximum concentration); t_(max) (time toC_(max)); t_(1/2) (half-life); AUC 0-24 (area under the curve from timeof dosing and 24 hours after dosing), and “24 h exposure” is theconcentration measured 24 hours after dosing.

Therapeutically Effective Amount:

In the present context, the term “therapeutically effective amount” of acompound means an amount sufficient to alleviate, arrest, partly arrest,remove or delay the clinical manifestations of a given disease and itscomplications in a therapeutic intervention comprising theadministration of said compound. An amount adequate to accomplish thisis defined as “therapeutically effective amount”. Effective amounts foreach purpose will depend e.g. on the severity of the disease or injuryas well as the weight and general state of the subject.

In the context of the present invention, a “therapeutically effectiveamount” of the compound of formula (Id) indicates an amount of saidcompound of the invention that is able to provide an amount of compound(I) that is sufficient to alleviate, arrest, partly arrest, remove ordelay the clinical manifestations of a given disease and itscomplications when said compound of the invention is administered,preferably by the oral route, to a mammal, preferably a human.

Treatment and Treating:

In the present context, “treatment” or “treating” is intended toindicate the management and care of a patient for the purpose ofalleviating, arresting, partly arresting, removing or delaying progressof the clinical manifestation of the disease. The patient to be treatedis preferably a mammal, in particular a human being.

Conditions for Treatment:

The compound prepared by the process of the present invention isintended for treatment of neurodegenerative diseases and disorders suchas Parkinson's disease and/or other conditions for which treatment witha dopamine agonist is therapeutically beneficial.

Therapeutic indications include a variety of central nervous systemdisorders characterized by motor and/or non-motor disturbances and forwhich part of the underlying pathophysiology is a dysfunction of thestriatal-mediated circuitry. Such functional disturbances can be seen inneurodegenerative diseases such as but not limited to Parkinson'sdisease (PD), Restless leg syndrome, Huntington's disease, andAlzheimer's disease but also neuropsychiatric diseases such as, but notlimited to schizophrenia, attention deficit hyperactivity disorder anddrug addiction.

In addition to neurodegenerative diseases and disorders, otherconditions in which an increase in dopaminergic turnover may bebeneficial are in the improvement of mental functions including variousaspects of cognition. It may also have a positive effect in depressedpatients, and it may also be used in the treatment of obesity as ananorectic agent and in the treatment of drug addiction. It may improveminimal brain dysfunction (MBD), narcolepsy, attention deficithyperactivity disorder and potentially the negative, the positive aswell as the cognitive symptoms of schizophrenia.

Restless leg syndrome (RLS) and periodic limb movement disorder (PLMD)are alternative indications, which are clinically treated with dopamineagonists. In addition, impotence, erectile dysfunction, SSRI inducedsexual dysfunction, ovarian hyperstimulation syndrome (OHSS) and certainpituitary tumors (prolactinoma) are also likely to be improved bytreatment with dopamine agonists. Dopamine is involved in regulation ofthe cardiovascular and renal systems, and accordingly, renal failure andhypertension can be considered alternative indications for the compoundof formula (Id).

The invention encompasses use of the compound of formula (Id) obtainedby a process of the invention for treatment of the diseases anddisorders listed above.

Administration Routes

Pharmaceutical compositions comprising a compound of formula (Id),either as the sole active compound or in combination with another activecompound, may be specifically formulated for administration by anysuitable route such as the oral, rectal, nasal, buccal, sublingual,pulmonal, transdermal and parenteral (e.g. subcutaneous, intramuscular,and intravenous) route. In the context of the present invention the oralroute is the preferred route of administration.

It will be appreciated that the route will depend on the generalcondition and age of the subject to be treated, the nature of thecondition to be treated and the active ingredient.

Pharmaceutical Formulations and Excipients

In the following, the term, “excipient” or “pharmaceutically acceptableexcipient” refers to pharmaceutical excipients including, but notlimited to, carriers, fillers, diluents, antiadherents, binders,coatings, colours, disintegrants, flavours, glidants, lubricants,preservatives, sorbents, sweeteners, solvents, vehicles and adjuvants.

The present invention also provides a pharmaceutical compositioncomprising the compound of formula (Id), such as one of the compoundsdisclosed in the Experimental Section herein. The present invention alsoprovides a process for making a pharmaceutical composition comprising acompound of formula (Id). The pharmaceutical compositions according tothe invention may be formulated with pharmaceutically acceptableexcipients in accordance with conventional techniques such as thosedisclosed in Remington, “The Science and Practice of Pharmacy”, 22^(th)edition (2013), Edited by Allen, Loyd V., Jr.

The pharmaceutical composition comprising a compound of the presentinvention is preferably a pharmaceutical composition for oraladministration. Pharmaceutical compositions for oral administrationinclude solid oral dosage forms such as tablets, capsules, powders andgranules; and liquid oral dosage forms such as solutions, emulsions,suspensions and syrups as well as powders and granules to be dissolvedor suspended in an appropriate liquid.

Solid oral dosage forms may be presented as discrete units (e.g. tabletsor hard or soft capsules), each containing a predetermined amount of theactive ingredient, and preferably one or more suitable excipients. Whereappropriate, the solid dosage forms may be prepared with coatings suchas enteric coatings or they may be formulated so as to provide modifiedrelease of the active ingredient such as delayed or extended releaseaccording to methods well known in the art. Where appropriate, the soliddosage form may be a dosage form disintegrating in the saliva, such asfor example an orodispersible tablet.

Examples of excipients suitable for solid oral formulation include, butare not limited to, microcrystalline cellulose, corn starch, lactose,mannitol, povidone, croscarmellose sodium, sucrose, cyclodextrin,talcum, gelatin, pectin, magnesium stearate, stearic acid and loweralkyl ethers of cellulose. Similarly, the solid formulation may includeexcipients for delayed or extended release formulations known in theart, such as glyceryl monostearate or hypromellose. If solid material isused for oral administration, the formulation may for example beprepared by mixing the active ingredient with solid excipients andsubsequently compressing the mixture in a conventional tabletingmachine; or the formulation may for example be placed in a hard capsulee.g. in powder, pellet or mini tablet form. The amount of solidexcipient will vary widely but will typically range from about 25 mg toabout 1 g per dosage unit.

Liquid oral dosage forms may be presented as for example elixirs,syrups, oral drops or a liquid filled capsule. Liquid oral dosage formsmay also be presented as powders for a solution or suspension in anaqueous or non-aqueous liquid. Examples of excipients suitable forliquid oral formulation include, but are not limited to, ethanol,propylene glycol, glycerol, polyethylenglycols, poloxamers, sorbitol,poly-sorbate, mono and di-glycerides, cyclodextrins, coconut oil, palmoil, and water. Liquid oral dosage forms may for example be prepared bydissolving or suspending the active ingredient in an aqueous ornon-aqueous liquid, or by incorporating the active ingredient into anoil-in-water or water-in-oil liquid emulsion.

Further excipients may be used in solid and liquid oral formulations,such as colourings, flavourings and preservatives etc.

Pharmaceutical compositions for parenteral administration includesterile aqueous and nonaqueous solutions, dispersions, suspensions oremulsions for injection or infusion, concentrates for injection orinfusion as well as sterile powders to be reconstituted in sterilesolutions or dispersions for injection or infusion prior to use.Examples of excipients suitable for parenteral formulation include, butare not limited to water, coconut oil, palm oil and solutions ofcyclodextrins. Aqueous formulations should be suitably buffered ifnecessary and rendered isotonic with sufficient saline or glucose.

Other types of pharmaceutical compositions include suppositories,inhalants, creams, gels, dermal patches, implants and formulations forbuccal or sublingual administration.

It is requisite that the excipients used for any pharmaceuticalformulation comply with the intended route of administration and arecompatible with the active ingredients.

Doses:

In one embodiment, compound (Id) prepared by a process of the inventionis administered in an amount from about 0.0001 mg/kg body weight toabout 5 mg/kg body weight per day. In particular, daily dosages may bein the range of 0.001 mg/kg body weight to about 1 mg/kg body weight perday. The exact dosages will depend upon the frequency and mode ofadministration, the sex, the age, the weight, and the general conditionof the subject to be treated, the nature and the severity of thecondition to be treated, any concomitant diseases to be treated, thedesired effect of the treatment and other factors known to those skilledin the art.

A typical oral dosage for adults will be in the range of 0.01-100 mg/dayof a compound of the present invention, such as 0.05-50 mg/day, such as0.1-10 mg/day or 0.1-5 mg/day. Conveniently, the compounds of theinvention are administered in a unit dosage form containing saidcompounds in an amount of about 0.01 to 50 mg, such as 0.05 mg, 0.1 mg,0.2 mg, 0.5 mg, 1 mg, 5 mg, 10 mg, 15 mg, 20 mg or up to 50 mg of acompound of the present invention.

BRIEF DESCRIPTION OF FIGURES

FIG. 1: PK profiles in Wistar rats obtained after oral dosing accordingto Example 9. Profiles are based on mean plasma concentrations from 3subjects for each compound. X-axis: time (hours); Y-axis: plasmaconcentration of Compound (I) (pg/mL) obtained after dosing of thefollowing compounds ●: compound (Ia); ▴: compound (Ib); ♦: compound(Id).

FIGS. 2 and 3: Locomotor activity time-course (FIG. 2) and totaldistance travelled (FIG. 3) following treatment with vehicle (H₂O,p.o.), or compound (Id) (10, 30, 100 or 300 μg/kg, p.o.) and compared tostandard-of-care (SoC) treatments: apomorphine (APO, 3 mg/kg, s.c.),pramipexole (PPX, 0.3 mg/kg, s.c.). Animals were dosed at t=60 minutesafter a 60-min. habituation period in test chambers, and activity wasmonitored for 350 minutes thereafter. Data was evaluated by use of aKruskal-Wallis test with Dunn's Multiple Comparisons test, resulting inan overall P-value of <0.0001.

FIG. 2: X-axis: time (min); Y-axis: Distance travelled(cm)±SEM/5-minute-bins.

FIG. 3: Y-axis: Total distance travelled (cm)±SEM. Significance levelsfor post-hoc comparisons (relative to the vehicle group) are indicated:*<0.05, **<0.01, ***<0.001, ****<0.0001.

FIGS. 4 and 5: Relationships between plasma concentrations of compound(Id) and compound (I) and hyperactivity induced by compound (Id) (100μg/kg, p.o.) (FIG. 4) and the corresponding relationship between plasmaapomorphine concentrations and hyperactivity induced by apomorphine (3mg/kg, s.c.) (FIG. 5).

X-axis time (min); Y-axis left: Distance travelled(cm)±SEM/5-minute-bins; Y-axis right (FIG. 4): plasma concentration ofcompound (I) (pg/mL); Y axis right (FIG. 5): plasma concentration ofapomorphine (ng/mL).

□: Distance travelled (cm) ● plasma concentration.

FIG. 6: conversion of compound (Id) to compound (I) in rat (6a) andhuman (6b) hepatocytes.

X-axis time (min); Y-axis: concentration of compound (I) (pg/mL).

FIG. 7: conversion of compound (Id) in rat (7a) and human (7b) wholeblood.

X-axis time (min); Y-axis: concentration of compound (I) (pg/mL).

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a process for manufacturing thecompound(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylicacid with the formula (Id) below and salts thereof

The compound of formula (Id) is a prodrug of(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-diol[compound (I)] which is a dual D1/D2 agonist within vitro data listed inTable 2.

The inventors have observed that compound (I) is conjugated in rat andhuman hepatocytes to sulfate and glucuronide derivatives includingcompound (Id). The conjugates have shown to be converted to compound (I)by conjugation and de-conjugation in the body.

Glucuronide and sulfate derivatives are commonly known to be unstable inthe intestine. The derivatives are formed as highly polar and solublemetabolites to facilitate the elimination of compounds from the body andare consequently easily excreted. For example, in bile duct cannulatedrats, glucuronide and sulfate conjugates are often found in bile whiletheir de-conjugate (i.e. the parent compound) is found in faeces. Theback-conversion of glucuronide and sulfate conjugates in the intestineto the parent compound which is then sometimes subsequently reabsorbed,is known as part of the enterohepatic re-circulation process. Asmentioned earlier, oral dosing of phenethyl catecholamines, such asapomorphine, has generally proven unsuccessful due to lowbioavailability. Likewise, compound (I) suffers from low oralbioavailability (Liu et al., Bioorganic Med. Chem. (2008), 16:3438-3444). With this in mind and considering the instability ofglucuronide and sulfate conjugates in the gastrointestinal tract, itwould not be expected that oral dosing of glucuronide and sulfateconjugates of compound (I) can be used to achieve sufficient plasmaexposure of the compound.

The principle of applying glucuronide derivatives as prodrugs for oraldelivery has been explored for retinoic acid (Goswami et al., J.Nutritional Biochem. (2003) 14: 703-709) and for morphine (Stain-Texieret al., Drug Metab. and Disposition (1998) 26 (5): 383-387). Bothstudies showed very low exposure levels of the parent compounds afteroral dosing of the derivatives. Another study suggests the use ofbudenoside-β-D-glucuronide as a prodrug for local delivery of budenosideto the large intestine for treatment of Ulcerative Colitis based on poorabsorption of the prodrug itself from the intestinal system (Nolen etal., J. Pharm Sci. (1995), 84 (6): 677-681).

Nevertheless, surprisingly, it has been observed that oral dosing ofcompound (Id) which has been identified as a metabolite of compound (I)in rats and minipigs provides a systemic exposure of compound (I) inplasma, suggesting the usefulness of said compound as an orally activeprodrug of compound (I).

The plasma profile of compound (I) resulting from oral dosing ofcompounds (Ia) and (Ib) and compound (Id) to Wistar rats according toExample 9 are shown in FIG. 1. For all the compounds, the doses werecorrected by molecular weight to equal a dose of 300 μg/kg of compound(Ib) corresponding to 287 μg/kg of compound (I). The inventors havefound that oral dosing of compounds (Ia) and (Ib) to Wistar rats resultsin early and high peak concentrations of compound (I). Such high peakconcentrations are in humans likely to be associated with dopaminergicside effects such as for example nausea, vomiting and light headedness.In contrast, dosing of the compound (Id), results in a slower absorptionrate avoiding rapid peak concentrations accompanied by a sustainedexposure of compound (I) in plasma. Additionally, the plasma exposure ofcompound (I) in Wistar rats is maintained throughout 24 hours althoughthe obtained AUC of compound (I) is generally lower than the AUCobtained after dosing of compound (Ib). However, since the peakconcentrations of compound (I) which are expected to drive the sideeffects are lower, higher doses might be administered of the compound(Id) to potentially achieve higher overall plasma concentrations ofcompound (I) compared to what is achievable from dosing compounds (Ia)and (Ib). When investigating PK properties of compound (Ic), theinventors found that the plasma concentrations of compound (I) wereextremely low, leaving compound (Ic) unsuitable as a prodrug of compound(I) for oral administration and confirming that the oral bioavailabilitydemonstrated for the compound of formula (Id) was highly unpredictable.PK parameters for the PK studies in Wistar rats are listed in Table 3.

In vivo conversion of compound (Id) to compound (I) has also beenobserved by after oral dosing of compound (Id) in minipigs.

Bioconversion of compound (Id) in human is supported by the Experimentsof Example 6 indicating conversion to the compound of formula (I) in ratand human hepatocytes and in rat and human blood (FIGS. 6 and 7).

Thus, in conclusion, the compound of formula (Id) is useful as an orallyactive prodrug of compound (I) and has been observed in rats to providea PK profile avoiding the peak C_(max) observed for the known prodrugs(Ia) and (Ib) and providing a significantly higher AUC of compound (I)than compound (Ic).

Compound (Id) has further been explored in the rat locomotor activityassay according to Example 10. The assay demonstrated a dopaminergiceffect obtained after oral administration of compound (Id) c.f. FIGS. 2,3 and 4. The fact that the compound of formula (Id) possesses no invitro dopaminergic activity c.f. example 9 and Table 3, furtherindicates that the effect of compound (Id) in the rat locomotor activityassay is obtained by conversion of compound (Id) to compound (I).

Finally, an important issue associated with the prior art compound (Ib)is that this compound is an agonist of the 5-HT2B receptor. Since 5-HT2Breceptor agonists have been linked to pathogenesis of valvular heartdisease (VHD) after long term exposure, such compounds are not suitablefor use in the treatment of chronical diseases (Rothman et al.,Circulation (2000), 102: 2836-2841; and Cavero and Guillon, J.Pharmacol. Toxicol. Methods (2014), 69: 150-161). Thus, a furtheradvantage of the compounds of the invention is that these are not 5-HT2Bagonists c.f. example 8 and Table 2.

The compound of formula (Id) is useful in the treatment ofneurodegenerative diseases and disorders such as Parkinson's diseaseand/or other conditions for which treatment with a dopamine agonist istherapeutically beneficial. The compound, being suitable for oraladministration has the potential of providing a new treatment paradigmin Parkinson's Disease.

The invention provides a scalable synthesis of compound (Id), which mayavoid column chromatographic purification, while providing compound (Id)in high purity. The overall process starting from compound (I) isillustrated in brief in Scheme 2 below.

X is selected from the group consisting of Cl, Br and I.

Y is an alkali metal preferably selected from the group consisting ofLi, Na and K.

A process for the preparation of compound (I) to be used in step 1) hasbeen disclosed in WO 2009/026934.

Table 1 below provides an overview of the compounds (A2), (A3), (A4) and(A5) which are intermediates with the following respective compoundnames.

TABLE 1 Overview of intermediates Abbreviated name Chemical nameStructure drawing (A2) (4aR,10aR)-6,7- bis(benzyloxy)-1-propyl-1,2,3,4,4a,5,10,10a- octahydrobenzo[g]quinoline;

(A3) (4aR,10aR)-7-(benzyloxy)-1- propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6- ol

(A3-HI) hydroiodide salt of compound (A3)

(A4) (2S,3R,4S,5S,6S)-2- (((4aR,10aR)-7-(benzyloxy)-1-propyl-1,2,3,4,4a,5,10,10a- octahydrobenzo[g]quinolin-6- yl)oxy)-6-(methoxycarbonyl)tetrahydro- 2H-pyran-3,4,5-triyl triacetate

(A5) (2S,3S,4S,5R,6S)-6- (((4aR,10aR)-7-(benzyloxy)-1-propyl-1,2,3,4,4a,5,10,10a- octahydrobenzo[g]quinolin-6-yl)oxy)-3,4,5- trihydroxytetrahydro-2H- pyran-2-carboxylic acid

(A5-Y) alkali salt of compound (A5)

The reactant(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate, used in step 3, can be purchased at Sigma-Aldrich (CASNumber: 92420-89-8).

Step 1

In step 1) the inventors found that compound (I), surprisingly could besubjected to a dibenzylation reaction with benzyl halogenide such as forexample benzyl chloride or benzyl bromide affording compound (A2),without significant loss to quaternization of the tertiary amine moiety.There are examples of dibenzylations of 3-alkyl substituted catecholsreported, in which there are no electron-withdrawing groups attacheddirectly to the aromatic ring of the catechol, while no examples havebeen reported with the additional structural presence of an unprotectedamine. Loev, B et al. (JACS, 1956, 78, p. 6095-6097), Imai, K. et al(RSC Adv., 2017, 7, 17968-17979), Mandell, L. et al (J. Org. Chem.,1982, 47, 731-734), Loozen, B. et al. (Recueil des Travaux Chimiques desPays Bas, 1982, 101, 298-310), Montanari, S. et al. (U.S. Pat. No.5,747,513, 1998, A), and Shimada, X. et al. (Chemical and PharmaceuticalBulletin, 1986, 34, 179-187) reported dibenzylation using benzyl bromidein DMF, acetone, or EtOH with potassium carbonate as base, purifying theproduct using silica gel column chromatography.

X is selected from Cl, Br and I

The reaction occurs in an organic solvent preferably selected fromacetonitrile (MeCN), dimethylformamide (DMF) or methyl isobutyl ketone(MIBK) in the presence of a base, preferably an inorganic base such asfor example sodium or potassium hydroxide (NaOH or KOH) or potassiumcarbonate (K₂CO₃).

Step 2

Step 2) is a selective deprotection and there are only a few examples ofselective mono debenzylations of a 3-substituted dibenzylated catecholreported. Hitoshi, T et al. (Chem Pharm Bull, 1986, 628) reported aselective debenzylation using trifluoroacetic acid (TFA, 86:7 ratio ofregio-isomers, 86% yield) or aluminum trichloride (AlCl₃, 85:7 ratio ofregio-isomers, 85% yield) in benzene and aluminum tribromide (AlBr₃) innitrobenzene (80% yield, one regio-isomer) or carbon disulfide (78%yield, one regio-isomer). The large scale use of solvents such asbenzene, nitrobenzene, and carbon disulfide are not recommended, due tocarcinogenic and toxicological characteristics. The use oftrifluoroacetic acid is optimal due to environmental concerns andaluminum trichloride and aluminum tribromide, both would require aqueousworkup at neutral or basic pH, which is unfavourable in regards tostability and isolation of (A3). Montanari, S. et al. (U.S. Pat. No.5,747,513) reported using trimethylsilyl iodide (TMSI) indichloromethane and purifying the crude product using silica gel columnchromatography. The use of silica gel column chromatography in isolationand purification limits the scalability of the process. The currentinvention describes a scalable process in which mono-debenzylation maybe achieved with high selectivity (>99:1) in the presence of anunprotected amine.

In a preferred embodiment, the HI salt of (A3) is directly isolated as astable solid. The isolation of the HI salt of compound (A3) as a solidallows for a high yield, thus avoiding tedious purification using silicagel column chromatography.

In summary, step 2 provides a scalable and selective mono-debenzylationof compound (A2), mediated by a debenzylation agent such astrimethylsilyl iodide resulting selectively in a high yield of compound(A3), which may be isolated as a hydroiodide salt (A3-HI).

The reaction is preferably performed under nitrogen atmosphere in anorganic solvent such as for example acetonitrile (MeCN),dichloromethane, or chloroform (CHCl₃). The compound is directlyobtained as the hydroiodide salt in high purity without the use ofcolumn chromatography.

Step 3

In step 3) compound (A3) is coupled with(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate in an organic solvent, such as for example dichloromethane or(trifluoromethyl)benzene, promoted by a protic acid such astrifluoromethanesulfonic acid or a Lewis acid and protic acidcombination such as boron trifluoride diethyl etherate and hydroiodideto obtain compound (A4).

A further challenge is the removal of the excess sugar residues withoutthe use of column chromatography. Column chromatography can be avoidedby extracting the product into a solution with a pH between 1-5, such asbetween 2-4, such as between 2.5-3.5, such as between 2.7-3.2 such asabout 3. Optimal pH conditions can be obtained by for example extractingthe product into a solution of an acid with pKa between 2-4, such asbetween 2.5-3.5, such as between 2.7-3.2, such as about 3; such as forexample a citric acid solution.

Thereby the sugar residues can be removed and followed by pHneutralization of the solution compound (A4) can be isolated.

Step 4

In step 4) compound (A4) is taken directly further for the deprotectionof the sugar moiety followed by precipitation of a salt of compound (A5)such as an alkali salt, preferably a potassium salt.

Y is an alkali metal preferably selected from Li, Na and K

The inventors found that by precipitation of the compound as thepotassium salt from an aqueous solution the compound could be isolatedvia filtration and obtained in high purity. Glucuronic acid conjugatesare typically very water soluble (Stachulski, A. V. et al. Nat. Prod.Rep., 2013, 30, 806-848), it is therefore surprising that A5precipitates as potassium salt directly from water, thereby isolating A5without the use of reverse phase column chromatography in high purity.

Step 5

In step 5) compound (A5-Y) is debenzylated to afford compound (Id).

Debenzylation can be performed by hydrogenation in water e.g. in thepresence of Pd/C and hydrogen. The end product can be isolated viafiltration and neutralized with an acid such as for example HCl, therebyaffording compound (Id) as a heptahydrate.

Embodiments of the Invention

In the following, embodiments of the invention are disclosed. The firstembodiment is denoted E1, the second embodiment is denoted E2 and soforth.

E1. A process for the preparation of compound (Id), or apharmaceutically acceptable salt thereof with the formula below

from compound (I), or a salt thereof with the formula below

comprising the following step

-   -   1) reacting compound (I), or a salt thereof with benzyl        halogenide to obtain compound (A2) according to the reaction        scheme below

-   -   wherein is selected from GI, r and I. A        E2. A process for the manufacturing the compound of formula (A2)        below comprising the following step    -   1) reacting compound (I), or salt thereof with benzyl halogenide        to obtain compound (A2) according to the reaction scheme below

wherein X is selected from Cl, Br and I.E3. The process according to any of embodiments 1-2, wherein:

-   -   a) said benzyl halogenide is benzyl chloride and X is Cl; or    -   b) said benzyl halogenide is benzyl bromide and X is Br.        E4. The process according to any of embodiments 1-3, wherein        said reaction takes place in an organic solvent such as for        example acetonitrile (MeCN), dimethylformamide (DMF) or methyl        isobutyl ketone (MIBK); and in the presence of a base such as        for example sodium or potassium hydroxide (NaOH or KOH) or        potassium carbonate (K₂CO₃).        E5. The process according to any of embodiments 1-4, wherein        compound (I) is in the form of the HCl salt as shown below

E6. The compound of formula (A2) below:

-   -   or a salt thereof.        E7. Use of a compound according to embodiment E6, in a process        for the manufacture of the compound of formula (Id).        E8. A process for the preparation of compound (Id) with the        formula below

from compound (I) with the formula below

comprising the following step

-   -   2) subjecting compound (A2) to a dibenzylation reaction to        obtain compound (A3), or a salt thereof according to the        reaction scheme below

E9. The compound of formula A3 below:

or a salt thereof.E10. The process according to embodiment 8, wherein the dibenzylationreaction comprises the steps of:

-   -   I) reacting trimethylsilyl iodide with compound (A2) to form a        mixture;    -   II) adding an alcohol to said mixture obtained from step 1) to        obtain compound (A3) or a salt thereof;    -   III) optionally isolating compound (A3) or a salt thereof.        E11. The process according to embodiment 10, wherein the alcohol        added to said mixture in step II) is MeOH or n-heptyl alcohol.        E12. The process according to embodiments 10 to 11, wherein        compound (A3) is obtained in the form of a hydroiodide salt        (A3-HI).

E13. A process for the manufacture of the compound of formula (A3-HI)below, comprising the following step2) reacting compound (A2) with trimethylsilyl iodide to obtain compound(A3-HI)

E14. The process according to any of embodiments 8-13, wherein saidreaction takes place under nitrogen atmosphere in an organic solventsuch as for example acetonitrile (MeCN), dichloromethane (CH₂Cl₂), orchloroform (CHCl₃).E15. The compound of formula A3 below:

or a salt thereof.E16. The compound according to embodiment 15 which is in the form of ahydroiodide salt depicted below

E17. Use of a compound according to any of embodiments 15-16 in aprocess for the manufacture of compound (Id).E18. A process for the preparation of compound (Id) with the formulabelow

from compound (I) with the formula below

comprising the following step

-   -   3) reacting compound (A3), or a salt thereof with        (2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyl        triacetate to obtain compound (A4) according to the reaction        scheme below

E19. A process for the manufacture of the compound of formula (A4)below, comprising the following step

-   -   3) reacting compound (A3), or a salt thereof with        (2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyl        triacetate according to the reaction scheme below to obtain        compound (A4) according to the reaction scheme below

E20. The process according to any of embodiments 18-19, wherein saidreaction takes place in an organic solvent such as for exampledichloromethane or (trifluoromethyl)benzene in the presence of a proticacid such as trifluoromethanesulfonic acid or a combination of a Lewisacid and protic acid such as for example boron trifluoride diethyletherate and hydroiodide.E21. The process according to any of embodiments 18-20 furthercomprising extracting the crude compound (A4) into a solution with pHbetween 1-5, such as between 2-4, such as between 2.5-3.5, such asbetween 2.7-3.2, such as about 3; and subsequently isolating compound(A4).E22. The process according to any of embodiments 18-20 furthercomprising extracting the crude compound (A4) into a solution of an acidwith pKa between 2-4, such as between 2.5-3.5, such as between 2.7-3.2,such as about 3; such as for example a citric acid solution; andsubsequently isolating compound (A4).E23. The compound of formula (A4) below:

or a salt thereof.E24. Use of a compound according to embodiment 23 in a process for themanufacture of compound (Id).E25. A process for the preparation of compound (Id) with the formulabelow

from compound (I) with the formula below

comprising the following step

-   -   4) reacting compound (A4), or a salt thereof with        alkali-hydroxide to obtain (A5-Y) according to the reaction        scheme below

-   -   wherein Y is selected from Li, Na and K.        E26. A process for the manufacture of the compound according to        formula (A5-Y) below, comprising the following step    -   4) reacting compound (A4), or a salt thereof with        alkali-hydroxide to obtain (A5-Y) according to the reaction        scheme below

-   -   wherein Y is selected from Li, Na and K.        E27. The process according to any of embodiments 25-26 wherein:    -   a) said alkali hydroxide is lithium hydroxide and Y is Li; or    -   b) said alkali hydroxide is sodium hydroxide and Y is Na; or    -   c) said alkali hydroxide is potassium hydroxide and Y is K.        E28. The process according to any of embodiments 25-27, wherein        compound (A5-Y) is isolated by precipitation from an aqueous        solution.        E29. The compound of formula A5 below:

-   -   or a salt thereof.        E30. The compound according to embodiment 29 which is in the        form of an alkali salt depicted below

-   -   wherein Y is selected from Li, Na and K.        E31. The compound according to embodiment 30 wherein Y is K.        E32. Use of a compound according to any of embodiments 29-31 in        a process for the manufacture of compound (Id)        E33. A process for the preparation of compound (Id) with the        formula below

from compound (I) with the formula below

comprising the following step

-   -   5) debenzylating compound (A5-Y) to obtain compound (Id)        according to the reaction scheme below

E34. The process according to embodiment 33, wherein said debenzylationis performed by hydrogenation in water e.g. in the presence of Pd/C andhydrogen at about 2 bar.E35. The process according to an of embodiments 33-34, wherein compound(Id) is isolated via filtration and neutralized with an acid such as forexample HCl, thereby affording compound (Id) as a heptahydrate.E36. A process for the preparation of compound (Id) from compound (I)comprising

-   -   step 1) according to any of embodiments 1 and 3-5; followed by    -   step 2) according to any of embodiments 8 to 12 and 14.        E37. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22.        E38. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28.        E39. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 4) according to any of embodiments 25 and 27-28; followed        by    -   step 5) according to any of embodiments 33-35.        E40. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 1) according to any of embodiments 1 and 3-5; followed by    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22.        E41. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28.        E42. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28; followed        by    -   step 5) according to any of embodiments 33-35.        E43. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 1) according to any of embodiments 1 and 3-5; followed by    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28.        E44. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28; followed        by    -   step 5) according to any of embodiments 33-35.        E45. A process for the preparation of compound (Id) from        compound (I) comprising    -   step 1) according to any of embodiments 1 and 3-5; followed by    -   step 2) according to any of embodiments 8 to 12 and 14; followed        by    -   step 3) according to any of embodiments 18 and 20-22; followed        by    -   step 4) according to any of embodiments 25 and 27-28; followed        by    -   step 5) according to any of embodiments 33-35.        E46.        (2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylic        acid heptahydrate.

Items

-   The following items further serve to describe the invention and    embodiments thereof.

Item 1. A process for preparation of compound (Id) with the formulabelow, or a pharmaceutically acceptable salt thereof

from compound (I) with the formula below, or a salt thereof

comprising the following step

-   -   1) reacting compound (I), or a salt thereof with benzyl        halogenide to obtain compound (A2) according to the reaction        scheme below

-   -   wherein X is selected from the group consisting of Cl, Br and I.

-   Item 2. A process for preparation of the compound of formula (A2)    below comprising the following step    -   1) reacting compound (I), or salt thereof, with benzyl        halogenide to obtain compound (A2) according to the reaction        scheme below

-   -   wherein X is selected from the group consisting of Cl, Br and I.

-   Item 3. The process according to any one of items 1-2, wherein:    -   a) said benzyl halogenide is benzyl chloride and X is Cl; or    -   b) said benzyl halogenide is benzyl bromide and X is Br.

-   Item 4. The process according to any one of items 1-3, wherein said    benzyl halogenide is benzyl chloride and X is Cl.

-   Item 5. The process according to any one of items 1-4, wherein said    reaction takes place in an organic solvent and in the presence of a    base.

-   Item 6. The process according to any one of items 1-5, wherein said    reaction takes place in an organic solvent selected from the group    consisting of acetonitrile (MeCN) or dimethylformamide (DMF) and    methyl isobutyl ketone (MIBK).

-   Item 7. The process according to any one of items 1-6, wherein said    reaction takes place in the presence of a base selected from the    group consisting of sodium hydroxide (NaOH), potassium hydroxide    (KOH) and potassium carbonate (K₂CO₃).

-   Item 8. The process according to any one of items 1-7, wherein said    reaction takes place in an organic solvent, such as for example    acetonitrile (MeCN), dimethylformamide (DMF) or methyl isobutyl    ketone (MIBK); and in the presence of a base, such as for example    sodium or potassium hydroxide (NaOH or KOH) or potassium carbonate    (K₂CO₃).

-   Item 9. The process according to any one of items 1-8, wherein said    organic solvent is methyl isobutyl ketone (MIBK), and said base is    potassium carbonate (K₂CO₃).

-   Item 10. The process according to any one of items 1-9, wherein    compound (I) is in the form of the HCl salt as shown below

-   Item 11. A compound of formula (A2) below:

-   -   or a salt thereof.

-   Item 12. Compound (A2) as obtained by the process according to any    one of items 2-10.

-   Item 13. Use of a compound according to item 11, in a process for    the manufacturing of the compound of formula (Id).

-   Item 14. A process for preparation of compound (Id) with the formula    below

-   -   from compound (I) with the formula below

-   -   the process comprising the following step:    -   2) subjecting compound (A2) to a debenzylation reaction to        obtain compound (A3), or a salt thereof, according to the        reaction scheme below

-   Item 15. The process according to item 14, wherein the debenzylation    reaction comprises the steps of:    -   I) reacting trimethylsilyl iodide with compound (A2) to form a        mixture;    -   II) adding an alcohol to said mixture obtained from step I) to        obtain compound (A3) or a salt thereof;    -   III) optionally isolating compound (A3) or a salt thereof.-   Item 16. The process according to item 15, wherein step I) takes    place in an organic solvent selected from the group consisting of    acetonitrile (MeCN), dichloromethane (CH₂Cl₂), and chloroform    (CHCl₃).-   Item 17. The process according to any of items 15-16, wherein    step I) takes place in an organic solvent such as acetonitrile    (MeCN).-   Item 18. The process according to any one of items 15-17, wherein    step I) takes place under nitrogen atmosphere.-   Item 19. The process according to any one of items 15-18, wherein    said reaction in step I) takes place under nitrogen atmosphere in an    organic solvent such as for example acetonitrile (MeCN),    dichloromethane (CH₂Cl₂), or chloroform (CHCl₃).-   Item 20. The process according to any one of items 15-19, wherein    the alcohol added to said mixture in step II) is selected from the    group consisting of MeOH, n-heptyl alcohol, and ethanol.-   Item 21. The process according to any one of items 15-20, wherein    the alcohol added to said mixture in step II) is MeOH or n-heptyl    alcohol.-   Item 22. The process according to any one of items 15-21, wherein    the alcohol added to said mixture in step II) is ethanol.-   Item 23. The process according to any one of items 15-22, wherein    isopropyl acetate is added to the compound (A3) obtained in step    II).-   Item 24. The process according to any one of items 15-23, comprising    step III), wherein compound (A3) or a salt thereof is isolated.-   Item 25. The process according to any one of items 15-24, wherein    compound (A3) is obtained in the form of a hydroiodide salt (A3-HI)    as shown in the formula below

-   Item 26. A process for preparation of the compound of formula (A3),    comprising the steps as defined by items 14-24.-   Item 27. A process for preparation of the compound of formula    (A3-HI) below, comprising the following step    -   2) reacting compound (A2) with trimethylsilyl iodide to obtain        compound (A3-HI)

-   Item 28. The process according to item 27, comprising one or more    steps as defined by any one of items 14-25.-   Item 29. A compound of formula (A3) below:

-   -   or a salt thereof.

-   Item 30. The compound according to item 28, wherein said compound is    the hydroiodide salt of the formula (A3-HI) below

-   Item 31. Compound (A3) as obtained by the process according to any    one of items 14-24.-   Item 32. Compound (A3-HI) as obtained by the process according to    any one of items 14-25.-   Item 33. Use of a compound according to any one of items 29-32 in a    process for preparation of compound (Id).-   Item 34. A process for preparation of compound (Id) with the formula    below

-   -   from compound (I) with the formula below

-   -   comprising the following step    -   3) reacting compound (A3) or a salt thereof with        (2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyl        triacetate to obtain compound (A4) according to the reaction        scheme below

-   Item 35. A process for preparation of the compound of formula (A4)    below, comprising the following step    -   3) reacting compound (A3) or a salt thereof, with        (2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyl        triacetate according to the reaction scheme below to obtain        compound (A4) according to the reaction scheme below

-   Item 36. The process according to any one of items 34-35, wherein    said reaction in step 3 takes place in an organic solvent such as    for example dichloromethane or (trifluoromethyl)benzene in the    presence of a protic acid such as trifluoromethanesulfonic acid or a    combination of a Lewis acid and protic acid such as for example    boron trifluoride diethyl etherate and hydroiodide.-   Item 37. The process according to any one of items 34-36, wherein    said organic solvent is (trifluoromethyl)benzene.-   Item 38. The process according to any one of items 34-37, wherein    said reaction in step 3 takes place in the presence of boron    trifluoride diethyl etherate.-   Item 39. The process according to any one of items 34-38, wherein    said reaction in step 3 takes place in the presence of    trifluoromethanesulfonic acid.-   Item 40. The process according to any one of items 34-39, further    comprising an additional subsequent step, of extracting the crude    compound (A4) into a solution with pH between 1-5, such as between    2-4, such as between 2.5-3.5, such as between 2.7-3.2, such as about    3; and subsequently isolating compound (A4).-   Item 41. The process according to any one of items 34-40, further    comprising an additional subsequent step, of extracting the crude    compound (A4) into a solution of an acid with pKa between 2-4, such    as between 2.5-3.5, such as between 2.7-3.2, such as about 3; such    as for example a citric acid solution; and subsequently isolating    compound (A4).-   Item 42. The compound of formula (A4) below:

-   -   or a salt thereof.

-   Item 43. Compound (A4) or a salt thereof as obtained by the process    according to any one of items 35 to 41.

-   Item 44. Use of a compound according to item 42 in a process for    preparation of compound (Id).

-   Item 45. A process for preparation of compound (Id) with the formula    below

-   -   from compound (I) with the formula below

-   -   comprising the following step    -   4) reacting compound (A4) or a salt thereof, with        alkali-hydroxide to obtain (A5-Y) according to the reaction        scheme below

-   -   wherein Y is selected from Li, Na and K.

-   Item 46. A process for preparation of the compound according to    formula (A5-Y) below, comprising the following step    -   4) reacting compound (A4), or a salt thereof with        alkali-hydroxide to obtain (A5-Y) according to the reaction        scheme below

-   -   wherein Y is selected from Li, Na and K.

-   Item 47. The process according to any of items 45-46 wherein:    -   a) said alkali hydroxide is lithium hydroxide and Y is Li; or    -   b) said alkali hydroxide is sodium hydroxide and Y is Na; or    -   c) said alkali hydroxide is potassium hydroxide and Y is K.

-   Item 48. The process according to any one of items 45-47, wherein    said alkali-hydroxide is potassium hydroxide and Y is K.

-   Item 49. The process according to any of items 45-58, wherein    compound (A5-Y) is isolated by precipitation from an aqueous    solution.

-   Item 50. The compound of formula A5 below:

-   -   or a salt thereof.

-   Item 51. The compound according to item 50 which is in the form of    an alkali salt depicted below

-   -   wherein Y is selected from the group consisting of Li, Na and K.

-   Item 52. The compound according to item 51, wherein Y is K.

-   Item 53. Compound (A5) or a salt thereof as obtained by the process    according to any one of items 45-49.

-   Item 54. Use of a compound according to any of items 50-51 in a    process for preparation of compound (Id).

-   Item 55. A process for preparation of compound (Id) with the formula    below

-   -   from compound (I) with the formula below

-   -   comprising the following step

-   5) debenzylating compound (A5-Y) to obtain compound (Id) according    to the reaction scheme below

-   Item 56. The process according to item 55, wherein said    debenzylation is performed by hydrogenation in water e.g. in the    presence of palladium on carbon (Pd/C) and hydrogen at about 2 bar.-   Item 57. The process according to an of items 55-56, wherein    compound (Id) is isolated via filtration and neutralized with an    acid such as for example HCl, thereby affording compound (Id) as a    heptahydrate.-   Item 58. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 1) according to any one of items 1 and 3-10; followed by    -   step 2) according to any one of items 14-25.-   Item 59. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41.-   Item 60. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any one of items 45 and 47-49.-   Item 61. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 4) according to any one of items 45 and 47-49; followed by    -   step 5) according to any one of items 55-57.-   Item 62. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 1) according to any one of items 1 and 3-10; followed by    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41.-   Item 63. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any of items 45 and 47-49.-   Item 64. A process for preparation of compound (Id) from    compound (I) comprising    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any of items 45 and 47-49; followed by    -   step 5) according to any one of items 55-57.-   Item 65. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 1) according to any of items 1 and 3-5; followed by    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any of items 45 and 47-49.-   Item 66. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any of items 45 and 47-49; followed by    -   step 5) according to any one of items 55-57.-   Item 67. A process for preparation of compound (Id) from    compound (I) comprising:    -   step 1) according to any of items 1 and 3-5; followed by    -   step 2) according to any one of items 14-25; followed by    -   step 3) according to any one of items 34 and 36-41; followed by    -   step 4) according to any of items 45 and 47-49; followed by    -   step 5) according to any one of items 55-57.-   Item 68.    (2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylic    acid heptahydrate.-   Item 69. The    (2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-(((4aR,10aR)-7-hydroxy-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-yl)oxy)tetrahydro-2H-pyran-2-carboxylic    acid heptahydrate as obtained by the process according to any one of    items 55-57.

All references, including publications, patent applications and patents,cited herein are hereby incorporated by reference in their entirety andto the same extent as if each reference were individually andspecifically indicated to be incorporated by reference and were setforth in its entirety (to the maximum extent permitted by law).

Headings and sub-headings are used herein for convenience only andshould not be construed as limiting the invention in any way.

The description herein of any aspect or aspect of the invention usingterms such as “comprising”, “having,” “including” or “containing” withreference to an element or elements is intended to provide support for asimilar aspect or aspect of the invention that “consists of”, “consistsessentially of” or “substantially comprises” that particular element orelements, unless otherwise stated or clearly contradicted by context(e.g., a composition described herein as comprising a particular elementshould be understood as also describing a composition consisting of thatelement, unless otherwise stated or clearly contradicted by context).

The use of any and all examples, or exemplary language (including “forinstance”, “for example”, “e.g.”, “such as” and “as such”) in thepresent specification is intended merely to better illuminate theinvention and does not pose a limitation on the scope of inventionunless otherwise indicated.

It should be understood that the various aspects, embodiments, items,implementations and features of the invention mentioned herein may beclaimed separately, or in any combination.

The present invention includes all modifications and equivalents of thesubject-matter recited in the claims appended hereto, as permitted byapplicable law.

EXPERIMENTAL SECTION Preparation of the Compound of Formula (Id) andIntermediates NMR Methods

QNMR (600 MHz): 1) Relaxation delay   40 sec 2) Acquisition time 3.76sec 3) Time domain 64k  4) Size 32k  5) Dummy scans 4  6) Scans 8  7)Pulse   30 deg

LC-MS Methods

Analytical LC-MS data were obtained using the methods identified below.

Method 550: LC-MS were run on Waters Aquity UPLC-MS consisting of WatersAquity including column manager, binary solvent manager, sampleorganizer, PDA detector (operating at 254 nM), ELS detector, and TQ-MSequipped with APPI-source operating in positive ion mode.

LC-conditions: The column was Acquity UPLC BEH C18 1.7 μm; 2.1×50 mmoperating at 60° C. with 1.2 ml/min of a binary gradient consisting ofwater+0.05% trifluoroacetic acid (A) and acetonitrile/water (95:5)+0.05%trifluoroacetic acid.

Gradient (linear): 0.00 min  10% B 1.00 min 100% B 1.01 min  10% B 1.15min  10% B Total run time: 1.15 minutes

Method 551: LC-MS were run on Waters Aquity UPLC-MS consisting of WatersAquity including column manager, binary solvent manager, sampleorganizer, PDA detector (operating at 254 nM), ELS detector, and TQ-MSequipped with APPI-source operating in positive ion mode.

LC-conditions: The column was Acquity UPLC HSS T3 1.8 μm; 2.1×50 mmoperating at 60° C. with 1.2 ml/min of a binary gradient consisting ofwater+0.05% trifluoroacetic acid (A) and acetonitrile/water (95:5)+0.05%trifluoroacetic acid.

Gradient (linear) : 0.00 min   2% B 1.00 min 100% B 1.15 min   2% BTotal run time: 1.15 minutes

Method 555: LC-MS were run on Waters Aquity UPLC-MS consisting of WatersAquity including column manager, binary solvent manager, sampleorganizer, PDA detector (operating at 254 nM), ELS detector, and TQ-MSequipped with APPI-source operating in positive ion mode.

LC-conditions: The column was Acquity UPLC BEH C18 1.7 μm; 2.1×150 mmoperating at 60° C. with 0.6 ml/min of a binary gradient consisting ofwater+0.05% trifluoroacetic acid (A) and acetonitrile/water (95:5)+0.05%trifluoroacetic acid.

Gradient (linear): 0.00 min  10% B 3.00 min 100% B 3.60 min  10% B Totalrun time: 3.6 minutes

Example 1: Preparation of Compound (A2) (Step 1) Example 1a

A 50 mL round-bottom flask with a magnetic stir bar was charged with HClsalt of compound (I) (775 mg, 2.60 mmol) and K₂CO₃ (1260 mg, 9.12 mmol).Then, a stopper was placed in the neck and the flask was evaporated andback filled with nitrogen followed by the introduction of dryacetonitrile (7.8 mL). Subsequently, benzyl chloride (682 mg, 620 μl,5.39 mmol) was added and the mixture was warmed to 50° C. for 18 hoursbefore it was cooled to room temperature and Et₃N (263 mg, 363 μl, 2.60mmol) was added and the mixture stirred for an additional hour at roomtemperature. Then, the mixture was diluted with heptane (5 mL) and water(5 mL) (three phases were observed-heptane in the top, acetonitrile inthe middle and water in the bottom) and the heptane/acetonitrile phasewas extracted with water (3×5 mL) (after one extraction with water theacetonitrile phase went into the water phase as expected). The combinedaqueous phases were extracted with heptane (3×5 mL) and the combinedorganic phases were washed with brine (5 mL) and concentrated. From theLC-MS it was observed that only triple benzylated by-product was presentin the water phase and from the LC-MS of the isolated solid it wasobserved that only the product was present. After concentration, asyrup/oil was obtained which solidified overnight upon standing undervacuum. This afforded crude compound (A2) (992 mg) as a solid.

LCMS (method 550): retention time (RT)=0.73 minutes, [M+H]⁺=442.6 m/z.

Example 1b

A one-necked 1 L round-bottom flask with a magnetic stir bar was chargedwith HCl salt of compound (I) (10.75 g, 36.1 mmol) and K₂CO₃ (17.5 g,126 mmol). The flask was evaporated and back filled with nitrogenfollowed by the introduction of dry DMF (107 mL). Subsequently, benzylchloride (9.41 g, 8.55 mL, 74.3 mmol) was added and the mixture wasstirred at room temperature for 18 hours, then warmed to 100° C. for 5hours and then cooled to room temperature and stirred for additional 19hours. Subsequently, additional K₂CO₃ (7.48 g, 54.1 mmol) and benzylchloride (6.85 g, 6.29 mL, 54.1 mmol) was added and the mixture wasstirred for 5 hours at 100° C. Then, the mixture was cooled to roomtemperature and water (500 mL) and heptane (250 mL) was added. Theaqueous phase was washed with heptane (3×100 mL) and the combinedorganic phases were washed with brine (100 mL), dried (Na₂SO₄),filtered, and concentrated to give an orange-brown syrup whichsolidified upon standing under vacuum. The crude product (Compound (A2))(14.6 g) was taken directly to the next step.

LCMS (method 550): RT=0.73 minutes, [M+H]⁺=442.6 m/z.

Example 1c

A 15 L reactor were charged with HCl salt of compound (I) (600 g, 2015mmol), K₂CO₃ (974 g, 7047 mmol), benzyl chloride (487 ml, 536 g, 4234mmol) and MIBK (4.8 L). A nitrogen atmosphere was established. Thereaction suspension was heated to 105° C. for 17 hours before cooled toroom temperature. Additional benzyl chloride (25 ml, 28 g, 221 mmol) wasadded and the reaction mixture was re-heated at 105° C. for another 18hours before cooled to room temperature. Cold water (4.8 L) was chargedto the reaction mixture and the mixture was stirred for 30 minutes. Thebottom water phase was discarded. 3M citric acid (3 L) was added and themixture was stirred well for 45 minutes. The phases were separated. Thebottom citric acid water phase was washed with a mixture of Me-THF (1.2L) and heptane (2.4 L). The slowly separating viscous citric acid waterphase was recharged to the empty 15 L reactor and Me-THF (3 L) wasadded. 25% aqueous ammonia (3 L) was added temperature rate-controlledat 20-38° C. to pH 10-11. Heptane (4.5 L) was added and after stirringfor 15 minutes the phases were separated. The organic phase was washedwith water (3 L) and then concentrated under reduced pressure/50° C. to1 L, approximately. Acetonitrile (1 L) was added and the mixture wasre-concentrated under reduced pressure/50° C. to approximately 0.9 L.Acetonitrile (2.5 L) was added and the crude product (Compound A2,approximately 800 g) in solution was taken directly into the next step.

Example 2: Preparation of Compound (A3-HI) (Step 2) Example 2a

A 1 L one-necked round-bottom flask was charged with a magnetic stir barand compound (A2) (11.54 g, 26.1 mmol). Then, a rubber stopper wasplaced in the flask and the flask was evaporated and back-filled withnitrogen three times. Subsequently, dry acetonitrile (115 mL) was addedand the mixture was stirred until all starting material was dissolved.Then, TMS-1 (13.23 g, 9.00 mL, 66.1 mmol) was added and the mixture wasstirred under nitrogen at room temperature for 17 hours in which aprecipitation was observed after the addition. Afterwards, n-heptylalcohol (15.18 g, 18.55 mL, 131 mmol) was added and the mixture wasstirred for 45 minutes in which the TMS capped product was desilylated.During the addition of n-heptyl alcohol the solid dissolved and after1-2 minutes a new solid was formed. Subsequently, 1:15 (v/v) isopropylacetate/heptane (160 mL) was added and the mixture was cooled (ice-bath)and stirred for 60 min. The precipitate was filtered off and the filtercake was washed with 1:15 (v/v) isopropyl acetate/heptane (50 mL). Thesolid was dried in the vacuum oven for 21 hours at 40° C. giving thecrude compound (A3-HI) (10.14 g).

Example 2b

A 1 L one-necked round-bottom flask was charged with a magnetic stir barand compound (A2) (11.9 g, 26.8 mmol). Then, a rubber stopper was placedin the flask and the flask was evaporated and back-filled with nitrogenthree times. Subsequently, dry MeCN (180 mL) was added and the mixturewas stirred until all starting material was dissolved, then, TMS-1 (14.7g, 10.0 mL, 73.4 mmol) was added and the mixture was stirred undernitrogen at room temperature for 2 hours in which a precipitate formed.Then, MeOH (5.5 mL) was added and the mixture was stirred for 1 hour.During the addition of MeOH the solid dissolved and a new solid wasformed. Subsequently, 1:15 (v/v) isopropyl acetate/heptane (160 mL) wasadded and the mixture was cooled (ice-bath) and stirred for 60 minutes.The precipitate was filtered off and washed with 1:15 (v/v) isopropylacetate/heptane (1×50 mL). The solid was dried in a vacuum oven at 40°C. giving compound (A3-HI) (7.6 g).

LCMS (method 550): RT=0.55 minutes, [M+H]⁺=352.5 m/z.

¹H NMR (600 MHz, Chloroform-d₃) δ 10.42 (bs, 1H), 7.43-7.33 (m, 5H),6.78 (d, J=8.3 Hz, 1H), 6.58 (d, J=8.3 Hz, 1H), 5.72 (s, 1H), 5.08 (s,2H), 3.71 (dd, J=15.1, 11.3 Hz, 1H), 3.58 (ddt, J=10.3, 4.0, 2.0, 1H),3.25-3.11 (m, 4H), 2.90 (m, 1H), 2.72 (qt, J=13.6, 3.8 Hz, 1H), 2.61(qdd, J=11.5, 5.5, 3.9 Hz, 1H), 2.26 (dd, J=11.70 Hz, 17.0 Hz 1H), 2.19(m, 1H), 1.97 (m, 2H), 1.75 (tdd, J=12.5, 7.4, 5.5 Hz, 1H), 1.39 (qd,J=13.5, 11.7, 3.9 Hz, 1H), 1.06 (t, J=7.3 Hz, 3H).

Example 2c

A 15 L reactor was charged with an acetonitrile solution (from example1c) of crude compound A2 (2821 g solution, approximately 800 g ofcompound A2, 1810 mmol). The solution was heated to reflux, and solventwas distilled off to a final volume of approximately 0.9 L. Acetonitrile(6 L) was added and the solution was heated to 30° C. A freshly preparedmixture of trimethylsilyl iodide (661 ml, 929 g, 4640 mmol) inisopropylacetate (1100 ml) was added over 5 minutes to the reactionmixture. The reaction mixture was stirred 3.5 hours at 30-32° C. andthen cooled to 25° C. and stirred overnight. The reaction mixture wassampled for HPLC analysis. At 25° C., the reaction mixture was quenchedby addition of ethanol (650 ml) which shortly resulted in a clearsolution but was followed by precipitation of the product. The slurrywas stirred 2 hours at 28° C. and then isopropyl acetate (7 L) wasadded. The slurry was stirred 1 hour at 28° C. and then cooled slowlyovernight to room temperature. The slurry was cooled to 15° C. andstirred 2 hours followed by filtration. The filter cake was washed witha mixture of acetonitrile/isopropyl acetate (1:2, 3 L) and thenisopropyl acetate (1 L). The solid was dried in the vacuum oven for 3days at 40° C. which afforded compound (A3-HI) (632 g).

Liberation of Free Base Form of(4aR,10aR)-7-(benzyloxy)-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-olfrom Hydroiodide Salt

A 250 mL round-bottom flask was charged with a magnetic stir bar,compound (A3-HI) (6.00 g, 12.52 mmol) and K₂CO₃ (1.82 g, 13.14 mmol)followed by the introduction of isopropanol (46.8 g, 60.0 ml, 779 mmol)which afforded a slurry. The slurry was stirred for 30 minutes before 5%brine (40 mL) was added. The slurry was stirred at room temperature foradditionally 30 minutes before the two-phased slurry was poured into aseparation funnel. Then, isopropyl acetate (60 mL) was added and theseparation funnel was shaken and the two phases were separated and theorganic phase was heated with a heating gun in order to dissolve all theproduct. Then, the organic phase was washed with 5% brine (10 ml) (theorganic phase was reheated with a heating gun after each wash) andconcentrated to a solid (crude 4.86 g). The crude product was dried inthe vacuum oven for 18 h which afforded compound (A3) as a solid (4.78g). The crude product was used as such.

¹H NMR (600 MHz, Chloroform-d₃) δ 7.40 (m, 4H), 7.36 (m, 1H), 6.75 (d,J=8.3 Hz, 1H), 6.60 (d, J=8.3 Hz, 1H), 5.72 (s, 1H), 5.08 (s, 2H), 3.14(dd, J=15.7, 4.8 Hz, 1H), 3.02 (d, J=11.6 Hz, 1H), 2.98 (dd, J=17.5, 5.1Hz, 1H), 2.76 (ddd, J=13.2, 10.4, 6.0 Hz, 1H), 2.65 (t, J=13.5 Hz, 1H),2.53 (td, J=12.9, 12.0, 5.5 Hz, 1H), 2.31 (td, J=11.0, 4.3 Hz, 1H), 2.23(dd, J=17.3, 11.6 Hz, 2H), 1.95 (m, 1H), 1.72 (m, 3H), 1.54 (qdd,J=13.8, 11.4, 6.2 Hz, 2H), 1.15 (m, 1H), 0.90 (t, J=7.4 Hz, 3H).

Example 3: Preparation of Compound (A4) (Step 3) Example 3a

Compound (A3-HI) (6.20 g, 12.9 mmol) and(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate (24.8 g, 51.7 mmol) were suspended in(trifluoromethyl)benzene (112 mL), and cooled to 2° C. Then borontrifluoride diethyl etherate (2.29 g, 2.05 ml, 16.2 mmol) was addedunder a nitrogen atmosphere and the mixture was stirred at 2° C. for 20minutes, then warmed to 25° C. and stirred overnight under nitrogen.After a total of 21 hours, the mixture was cooled to 5° C. and quenchedby the addition of triethylamine (6.22 g, 8.6 mL, 61.4 mmol) andmethanol (15.5 mL), the cooling bath was removed and the mixture wasstirred for 1 hour and 10 minutes, then water (90 mL) was added. Theorganic phase was washed with water (2×65 mL) and the combined aqueousphase was extracted with (trifluoromethyl)benzene (25 mL). The combinedorganic phases were extracted with concentrated aqueous citric acid (82mL, 262 mmol, 3.18 molar) and the mixture was stirred for 20 minutes.The organic phase was extracted with additional concentrated aqueouscitric acid (61.0 mL, 194 mmol, 3.18 molar). THF/n-heptane (2:1, 50 mL)was added to the citric acid phase, and the mixture was cooled to 5° C.and slowly neutralized with aqueous ammonia (125 ml, 0.166 mol, 25%)with high stirring (>500 rpm) and temperature <16° C. until pH=7.8. Theaqueous phase was extracted with additional THF/n-heptane (2:1, 50 mL)and the combined organic phase was dried (Na₂SO₄), filtered andevaporated to dryness in vacuo affording crude compound (A4) (10.6 g).

LC-MS (method 555): RT=2.18 minutes, [M+H]⁺=668.4 m/z.

Example 3b Prepared from Free Base of(4aR,10aR)-7-(benzyloxy)-1-propyl-1,2,3,4,4a,5,10,10a-octahydrobenzo[g]quinolin-6-ol

A suspension of dried compound (A3) (2.00 g, 5.69 mmol) and(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate (6.81 g, 14.23 mmol) in (trifluoromethyl)benzene (36 mL) wascooled to 0° C. under nitrogen. Subsequently, trifluoromethanesulfonicacid (1.281 g, 0.758 mL, 8.54 mmol) was added dropwise in which theslurry dissolved fast followed by the formation of a new precipitateafter 10 minutes. The mixture was stirred for 1 h at 0° C. undernitrogen. LC-MS indicated full conversion of the starting material after1 h. Subsequently, Et₃N (2.61 g, 3.60 mL, 25.8 mmol) and MeOH (3.96 g,5.00 ml, 124 mmol) were added and the ice-bath was removed. The mixturewas stirred for 30 minutes at room temperature. Then, water (28 mL) wasadded and the two phases were separated. The organic phase was washedwith water (28 mL) and the combined aqueous phases were extracted with(trifluoromethyl)benzene (12 mL). To the combined organic phases wasadded 3.18 M citric acid (26.0 mL, 83 mmol, 3.18 M) and the mixture wasstirred for 25 minutes. The two phases were separated and the organicphase was extracted additionally with 3.18 M citric acid (12 mL, 38.2mmol, 3.18 molar). Then, isopropyl acetate (26 mL) was added to theaqueous phase and the solution was cooled on ice. Subsequently, 25%ammonia (0.388 g, 0.493 ml, 5.69 mmol, 25%) was added over the course of1.5 hours until pH 7.5 was reached. The two phases were separated andthe aqueous phase was extracted with isopropyl acetate (26 mL). Thecombined organic phases were dried over Na₂SO₄, filtered andconcentrated to a brown foam which was left under vacuum overnight(crude: 5.00 g). This afforded the crude compound (A4) (5.00 g). Thecrude product was used directly in example 4b.

LC-MS (method 555): RT=2.18 minutes, [M+H]⁺=668.3 m/z.

Example 4: Preparation of Compound (A5-K) (Step 4) Example 4a

Compound (A4) (10.6 g, 8.68 mmol, 54.5% (w/w)) was dissolved in THF(45.5 mL)/n-heptane (4.5 mL) and H₂O (50 mL) was added. The mixture wascooled to 6° C. and aqueous potassium hydroxide (9.52 g, 6.52 ml, 78mmol, 46%) was added and the mixture was slowly warmed to roomtemperature over a period of 2.5 hours. n-Heptane (10 mL) was addedresulting in phase separation. The organic phase was discarded. Theaqueous phase was washed with THF:n-heptane (25 mL, 4:1) and thenconcentrated (THF removed) in vacuo at 42° C., resulting inprecipitation. The mixture was stirred at 0° C. for 20 minutes, thenfiltered affording a solid, which was dried in the vacuum oven for 3hours affording compound (A5-K) (4.8 g).

LC-MS (method 550): RT=0.41 minutes, [M+H]⁺=528.4 m/z.

¹H NMR (600 MHz, Deuterium Oxide) δ 7.42-7.26 (m, 5H), 6.89 (d, J=8.5Hz, 1H), 6.82 (d, J=8.5 Hz, 1H), 5.04 (d, J=2.8 Hz, 2H), 4.91-4.88 (m,1H), 3.53-3.45 (m, 4H), 3.42-3.32 (m, 1H), 3.31-3.17 (m, 3H), 3.11 (td,J=11.3, 5.3 Hz, 1H), 3.05-2.93 (m, 2H), 2.69 (dd, J=15.7, 11.0 Hz, 1H),2.26 (dd, J=17.6, 11.7 Hz, 1H), 1.93 (t, J=14.2 Hz, 2H), 1.85-1.66 (m,3H), 1.61 (tt, J=12.5, 6.3 Hz, 1H), 1.30 (dd, J=17.6, 8.1 Hz, 1H), 0.90(td, J=7.4, 1.5 Hz, 3H).

Example 4b

Crude compound (A4) obtained from example 3b (5.0 g, 3.62 mmol, QNMRpurity 48.4%) was suspended in THF (12 mL), water (12 mL). n-Heptane(0,813 g, 1,189 ml, 8.12 mmol) was added and the solution was cooled to0° C. Subsequently, KOH (2.21 g, 1.52 mL, 18.12 mmol, 46% solution) wasadded over the course of 2 minutes and the mixture was stirred for 4hours at 1° C. LC-MS didn't indicated full conversion and therefore moreKOH (2.91 g, 2.0 mL, 23.87 mmol, 46% solution) was added and the mixturewas stirred for additionally 2 hours in which all the starting materialwas consumed. The mixture was transferred to a separation funnel andn-heptane (12 mL) was added resulting in a phase separation. The twophases were separated. The aqueous phase was washed with 4:1 THF (5mL)/n-heptane (1.2 mL) and then the brown aqueous phase was concentrated(to remove any THF) in vacuo. The mixture was stirred at roomtemperature for 3 days and a precipitate was observed before the mixturewas cooled to 0° C. and left for 45 minutes. Then, the precipitate wasfiltered off affording a white solid, which was dried in the vacuum ovenovernight at 40° C. to give compound (A5-K) as a white solid (1.98 g).

LC-MS (method 555): RT=1.54 minutes, [M+H]⁺=528.3 m/z.

¹H NMR (600 MHz, Deuterium Oxide) δ 7.47-7.36 (m, 5H), 6.88 (d, J=8.6Hz, 1H), 6.83 (d, J=8.5 Hz, 1H), 5.13 (m, 2H), 5.01 (d, J=7.9 Hz, 1H),3.59 (m, 1H), 3.54 (m, 1H), 3.47 (td, J=9.2, 0.7 Hz, 1H), 3.42 (dd,J=9.8, 0.7 Hz, 1H), 3.23 (dd, J=17.6, 4.8 Hz, 1H), 3.13 (dd, J=16.2, 5.1Hz, 1H), 2.98 (d, J=11.5 Hz, 1H), 2.69 (ddd, J=13.1, 11.4, 5.1 Hz, 1H),2.49 (dd, J=16.0, 11.1 Hz, 1H), 2.42 (ddd, J=13.1, 11.3, 5.0 Hz, 1H),2.28 (td, J=12.2, 2.8 Hz, 1H), 2.17 (m, 2H), 1.91 (m, 1H), 1.71 (m, 1H),1.60 (m, 1H), 1.50 (m, 2H), 1.43 (m, 1H), 1.08 (qd, J=13.0, 4.0 Hz, 1H),0.85 (t, J=7.3 Hz, 3H).

Example 4c

Compound (A3-HI) (360 g, 751 mmol) and(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate (1440 g, 3008 mmol) were suspended in(trifluoromethyl)benzene (5760 mL), and cooled to 2° C. Then a mixtureof boron trifluoride diethyl etherate (133 g, 116 ml, 940 mmol) in(trifuoromethyl)benzene (720 mL), was added under a nitrogen atmosphereover 25 minutes. The mixture was stirred at 2° C. for 60 minutes, thenwarmed to 22° C. and stirred 2 hours. The reaction mixture was warmed to27° C. stirred overnight under nitrogen. After a total of 23 hours at22-27° C., the reaction mixture was cooled to 2° C. and quenched by theaddition of first triethylamine (453 g, 624 mL, 4477 mmol) and thenafter 15 minutes methanol (494 g, 624 mL, 15410 mmol). The resultingclear solution was warmed to 21° C. and stirred 3.5 hours. Water (4300mL) was added and the mixture was stirred 30 minutes. The mixture wasleft separating overnight at 25° C. The organic phase was washed withwater (2.5 L). To the organic phase was added 3M of aqueous citric acid(3.6 L) and the mixture was stirred 25 minutes. To the mixture wereadded THF (1440 mL) and heptane (1440 mL) and the mixture was stirred 10minutes. The citric acid water phase was kept. To the organic phase wasadded 3M of aqueous citric acid (2.4 L) and the mixture was stirred 10minutes. The organic phase was discarded. To the combined citric acidwater phases were added THF (1080 mL) and heptane (1080 mL) and themixture was stirred 10 minutes. The organic phase was discarded. To thecitric acid water phase was added THF (2900 mL) and heptane (720 mL) andthe mixture was cooled to 5° C. In 3 hours, 25% aqueous ammonia (4.7 L)was added slowly to a pH of 9-9.5 keeping the temperature below 18° C.The phases were separated and the water phase re-extracted with amixture of THF (1140 mL) and heptane (360 mL). The combined organicphases were washed with a mixture of water (2.2 L) and 25% aqueousammonia (360 mL) and then two times with 5% NaCl (2×1.8 L). The phaseswere separated. To the organic phase was added THF (5.4 L) and water(1.8 L) and the mixture was cooled to 3° C. In 2 minutes, a mixture of12M KOH (424 mL) and water (1.8 L) was added to the cold reactionmixture. The reaction mixture was stirred at 3-5° C. for 1 hour and thenwarmed to 23° C. over 1.2 hours and stirred overnight at 23° C. Heptane(1.8 L) was added to the reaction mixture and stirring was continued for10 minutes. The organic phase was discarded. The water phase was washedwith a mixture of THF (1440 mL) and heptane (360 mL). The organic phasewas discarded. The water phase was heated to 50° C. and a vacuumdistillation was performed to remove residual THF. The water phase (4 L)was cooled to 20° C. and stirred overnight. The resulting productsuspension was cooled to 2° C. and filtered. The filter cake was washedtwo times with cold water (2×720 mL). The product was dried overnight at50° C. in vacuo, and compound (A5-K) was isolated (273 g).

Example 5: Preparation of Compound (Id) (Step 5) Example 5a (withoutSeeding)

Compound (A5) (0.59 g, 1.1 mmol) was dissolved in MeOH:water (2:1, 12mL) and active carbon (0.8 g) was added and the mixture stirred for 20minutes, then filtered through a plug of filter-aid and the solidswashed with MeOH:water (2:1, 4.5 mL). The combined filtrates were placedin the Asynth autoclave and Pd/C (0.30 g, 0.054 mmol, 1.9%) was addedand the mixture stirred for at 40° C., filled with nitrogen (threetimes), then hydrogen (three times, 6 bar). After 1 hour and 30 minutesthe mixture was filled with nitrogen three times, then filtered througha plug of filter aid and the solids were washed with MeOH/water (2:1, 15mL). The filtrate was evaporated to dryness. The solid was dissolved inwater (2 mL) and stirred overnight, then filtered affording compound(Id) (0.29 g).

LC-MS (method 551) RT=0.39 minutes, [M+H]⁺=438.3 m/z.

¹H NMR (600 MHz, Deuterium Oxide) δ 6.85 (d, J=8.4 Hz, 1H), 6.77 (d,J=8.4 Hz, 1H), 4.76 (d, J=7.5 Hz, 2H), 3.59-3.55 (m, 2H), 3.54-3.46 (m,3H), 3.38-3.28 (m, 2H), 3.28-3.19 (m, 2H), 3.20-3.01 (m, 2H), 2.74 (dd,J=15.0, 11.5 Hz, 1H), 2.30 (dd, J=17.5, 11.5 Hz, 1H), 2.00-1.92 (m, 2H),1.88-1.69 (m, 2H), 1.69-1.58 (m, 1H), 1.33 (dq, J=13.5, 4.0 Hz, 1H),0.92 (t, J=7.3 Hz, 3H).

Example 5b (with Seeding)

Compound (A5-K) (4.8 g, 8.5 mmol) and Pd/C Johnson-Matthey 5R39 (0.349g, 0.064 mmol, 1.94% Pd (w/w)) were suspended in H₂O (48 mL) and placedin an autoclave, filled with nitrogen three times, then hydrogen gas (2bar) three times and the mixture stirred at 40° C. for 1.5 hours. Themixture was backfilled with nitrogen and filtered through a plug into a100 mL round-bottom flask. The solids were rinsed with water (2×1.5 mL)and the combined aqueous phase was pH adjusted (from pH=10) to pH=6.2using aqueous HCl (2.1 ml, 8.5 mmol, 4 M) at room temperature and aseeding crystal of compound (Id) was added at 40° C. and precipitationoccurred. The mixture was stirred for 2 hours, then cooled to 2° C. Themixture was filtered and dried on the filter overnight with suctionaffording compound (Id) as a heptahydrate (3.90 g, 6.92 mmol, 82%, >99%purity based on QNMR).

LC-MS (method 551) RT=0.38 minutes, [M+H]⁺=438.3 m/z.

¹H NMR (600 MHz, Deuterium Oxide, maleic acid used as internal standard)δ 6.85 (d, J=8.4 Hz, 1H), 6.75 (d, J=8.4 Hz, 1H), 4.82 (d, J=2.8 Hz,2H), 3.83 (d, J=9.7 Hz, 1H), 3.61-3.54 (m, 2H), 3.54-3.48 (m, 2H), 3.34(dd, J=15.5, 5.0 Hz, 1H), 3.28 (dd, J=17.5, 5.0 Hz, 1H), 3.25-3.18 (m,2H), 3.01-3.08 (m, 2H), 2.73 (dd, J=15.5, 11.5 Hz, 1H), 2.29 (dd,J=17.5, 11.5 Hz, 1H), 1.99-1.90 (m, 2H), 1.89-1.69 (m, 3H), 1.70-1.58(m, 1H), 1.33 (dq, J=13.5, 4.0 Hz, 1H), 0.91 (t, J=7.3 Hz, 3H).

Example 6: In Vitro and In Vivo Characterization of Compound (Id)Example 6a: Conversion of the Compound of Formula (Id) in Rat and HumanHepatocytes

Compound (Id) was incubated at 1 μg/mL with hepatocytes from human orrat suspended in DMEM (Dulbecco's Modified Eagle Medium) with HEPES(4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) at pH 7.4. The cellconcentration at incubation was 1×10⁶ viable cells/mL. The incubationswere performed in glass tubes at 37° C. with a total incubation volumeof 3.5 mL and with duplicate incubations for each test item. The 3.5 mLof hepatocyte suspension was equilibrated for 10 minutes in a water bathset to 37° C. where after the incubations were initiated by adding 3.5μL of a stock solution of the test item in DMSO (Dimethyl sulfoxide) andgently inverting the tubes. The final solvent concentration in theincubations was 0.1% DMSO. Samples of 600 μL were withdrawn from theincubations at the pre-determined time points of 0.25, 5, 15, 30 and 60minutes after ensuring homogeneity of hepatocyte suspensions. Thewithdrawn volume was added to 1 mL Nunc cryotubes on wet ice containing60 μL of ice-cold ascorbic acid (100 mg/mL) and 30 μL of ice cold 100 mMsaccharic acid 1.4-lactone in 0.5 M citric acid. The tubes were mixedand 35 μL of a solution of ice cold 20% formic acid was added. The tubeswere mixed thoroughly and stored at −80° C. awaiting analysis. Analysismethod and Instrumentation used for analysis of (I) from dosing compound(Id) was the one described in Examples 9 and 10 below in the section“Instrumentation used for analysis of compound (I) from dosing ofcompound (1c) and (Id).”

FIG. 7 indicates a time dependent conversion to compound (I) from (Id)in both rat and human hepatocytes.

Example 6b: Conversion of the Compound of Formula (Id) in Fresh Rat andHuman Blood

Conversion of (Id) in human blood (average of 3 donors) and rat blood(average of 45 donors) to (1) was shown in fresh blood at 37° C. spikedwith 1 μg/mL of (Id). (1) was measured at 0, 5, 15, 30 and 60 minutes inisolated plasma. Analysis method and Instrumentation as described inExamples 9 and 10 below in the section “Instrumentation used foranalysis of compound (I) from dosing of compounds (1c) and (Id).”

FIG. 8 indicates a time dependent conversion to compound (I) from (Id),in both rat and human blood.

Example 7: Dopamine Agonist Activity Dopamine D1 Receptor Agonism

Dopamine D1 receptor agonism was measured using a HTRF cAMP from CisBiousing the protocol developed by HD Biosciences (China). Briefly, theassay is a homogeneous time resolved-fluorescence resonance energytransfer (HTRF) assay that measures production of cAMP by cells in acompetitive immunoassay between native cAMP produced by cells andcAMP-labeled with XL-665. A cryptate-labeled anti-cAMP antibodyvisualizes the tracer. The assay was performed in accordance withinstructions from manufacturer.

Test compounds were added to wells of microplates (384 format). HEK-293cells expressing the human D1 receptor were plated at 1000 cells/welland incubated 30 minutes at room temperature. cAMP-d2 tracer was addedto wells and followed by addition of Anti-cAMP antibody-cryptatepreparation and incubated for 1 hour at room temperature in dark. HTRFcAMP was measured by excitation of the donor with 337 nm laser (the “TRFlight unit”) and subsequent (delay time 100 microseconds) measurement ofcryptate and d2 emission at 615 nm and 665 nm over a time window of 200microseconds with a 2000 microseconds time window between repeats/100flashes). HTRF measurements were performed on an Envision microplatereader (PerkinElmer). The HTRF signal was calculated as theemission-ratio at 665 nm over 615 nm. The HTRF ratio readout for testcompounds was normalized to 0% and 100% stimulation using control wellswith DMSO-solvent or 30 μM dopamine. Test compound potency (EC₅₀) wasestimated by nonlinear regression using the sigmoidal dose-response(variable slope) using Xlfit 4 (IDBS, Guildford, Surrey, UK, model 205).

y=(A+((B−A)/(1+((C/x){circumflex over ( )}D))))

where y is the normalized HTRF ratio measurement for a givenconcentration of test compound, x is the concentration of test compound,A is the estimated efficacy at infinite compound dilution, and B is themaximal efficacy. C is the EC₅₀ value and D is the Hill slopecoefficient. EC₅₀ estimates were obtained from an independent experimentand the logarithmic average was calculated.

Dopamine D2 Receptor Agonism

Dopamine D2 receptor agonism was measured using a calcium mobilizationassay protocol developed by HD Biosciences (China). Briefly, HEK293/G15cells expressing human D2 receptor were plated at a density of 15000cells/well in clear-bottomed, Matrigel-coated 384-well plates and grownfor 24 hours at 37° C. in the presence of 5% CO₂. The cells wereincubated with calcium-sensitive fluorescent dye, Fluo8, for 60-90minutes at 37° C. in the dark. Test compounds were prepared at 3-foldconcentrated solution in 1×HBSS buffer with Ca²⁺ and Mg²⁺. Calcium Fluxsignal was immediately recorded after compounds were added from compoundplate to cell plate at FLIPR (Molecular Devices). The fluorescence datawere normalized to yield responses for no stimulation (buffer) and fullstimulation (1 μM of dopamine) of 0% and 100% stimulation, respectively.Test compound potency (EC₅₀) was estimated by nonlinear regression usingthe sigmoidal dose-response (variable slope) using Xlfit 4 (IDBS,Guildford, Surrey, UK, model 205).

y=(A+((B−A)/(1+((C/x){circumflex over ( )}D))))

where y is the normalized ratio measurement for a given concentration oftest compound, x is the concentration of test compound, A is theestimated efficacy at infinite compound dilution, and B is the maximalefficacy. C is the EC₅₀ value and D is the Hill slope coefficient. EC₅₀estimates were obtained from independent experiment and the logarithmicaverage was calculated.

Example 8: 5-HT2B Agonist Activity and Binding Assay 5-HT2B AgonistActivity Assay

Evaluation of the agonist activity of compounds (I), (Ia), (Ib), (Ic),and (Id) at the human 5-HT2B receptor was performed by Eurofins/Cerep(France) measuring the compound effects on inositol monophosphate (IP1)production using the HTRF detection method. Briefly, the human 5-HT2Breceptor was expressed in transfected CHO cells. The cells weresuspended in a buffer containing 10 mM Hepes/NaOH (pH 7.4), 4.2 mM KCl,146 mM NaCl, 1 mM CaCl₂, 0.5 mM MgCl₂, 5.5 mM glucose and 50 mM LiCl,then distributed in microplates at a density of 4100 cells/well andincubated for 30 minutes at 37° C. in the presence of buffer (basalcontrol), test compound or reference agonist. For stimulated controlmeasurement, separate assay wells contained 1 μM 5-HT. Followingincubation, the cells were lysed and the fluorescence acceptor(fluorophen D2-labeled IP1) and fluorescence donor (anti-IP1 antibodylabeled with europium cryptate) were added. After 60 minutes at roomtemperature, the fluorescence transfer was measured at lambda(Ex) 337 nmand lambda(Em) 620 and 665 nm using a microplate reader (Rubystar, BMG).The IP1 concentration was determined by dividing the signal measured at665 nm by that measured at 620 nm (ratio). The results were expressed asa percent of the control response to 1 μM 5-HT. The standard referenceagonist was 5-HT, which was tested in each experiment at severalconcentrations to generate a concentration-response curve from which itsEC₅₀ value is calculated as described above for dopamine functionalassays.

5-HT2B Binding Assay

Evaluation of the affinity of compounds for the human 5-HT2B receptorwas determined in a radioligand binding assay at Eurofins/Cerep(France). Membrane homogenates prepared from CHO cells expressing thehuman 5HT2B receptor were incubated for 60 minutes at room temperaturewith 0.2 nM [¹²⁵I](±)DOI (1-(4-iodo-2, 5-dimethoxyphenyl)propan-2-amine)in the absence or presence of the test compound in a buffer containing50 mM Tris-HCl (pH 7.4), 5 mM MgCl₂, 10 μM pargyline and 0.1% ascorbicacid. Nonspecific binding is determined in the presence of 1 μM (±)DOI.Following incubation, the samples were filtered rapidly under vacuumthrough glass fiber filters (GF/B, Packard) presoaked with 0.3%polyethyleneimine (PEI) and rinsed several times with ice-cold 50 mMTris-HCl using a 96-sample cell harvester (Unifilter, Packard). Thefilters were dried and counted for radioactivity in a scintillationcounter (Topcount, Packard) using a scintillation cocktail (Microscint0, Packard). The results are expressed as a percent inhibition of thecontrol radioligand specific binding. The standard reference compoundwas (±)DOI, which was tested in each experiment at severalconcentrations to obtain a competition curve from which its IC₅₀ iscalculated.

TABLE 2 In vitro activities for the compounds of formula (I), (Ia),(Ib), (Ic) and (Id) obtained according to Examples 7 and 8 D1 EC₅₀ D2EC₅₀ 5-HT2B EC₅₀ Compound (nM)/Emax (nM)/Emax (nM)/Emax Parent (I)  3.3/99%    1.3/91% 2900nM/50% compound Prodrugs in(Ia) >1000 >1000 >6000nM,    58% @ 30μM the state of (Ib) >100046nM/100%   3.8nM/79% the art (Ic) nd nd −5% @ 10μM Compound (Id)2700/98%   1100/92% −25% @ 10μM* obtained by the invention *indicatebinding affinity (% inhibition of control, specific binding atconcentration indicated) nd: not determined

Example 9: PK Experiments in Rats

For all the experiments, blood samples of approximately 0.68 mL weredrawn from the tail or sublingual vein and put into K₃EDTA tubes thathad been pre-cooled and prepared with stabilizing solution consisting of80 μL ascorbic acid and 40 μL 100 mM D-saccharic acid 1,4 lactone inwater. The tubes were inverted gently 6-8 times to ensure thoroughmixing and then placed in wet ice. The collecting tube was placed in wetice for up to 30 minutes until centrifugation. Once removed from the wetice the centrifugation was initiated immediately. Immediately after endof centrifugation the samples were returned to wet ice. Threesub-samples of 130 μL plasma were transferred to each of threeappropriately labelled cryo tubes containing 6.5 μL pre-cooled formicacid (20%) (the tubes were pre-spiked and stored refrigerated prior touse). The tube lid was immediately replaced and the plasma solution wasthoroughly mixed by inverting gently 6-8 times. The samples were storedfrozen at nominally −70° C. within 60 minutes after sampling.Centrifugation conditions at 3000 G for 10 minutes at 4° C. Plasma wasplaced on water-ice following collection. Final storage at approximately−70° C.

Plasma samples were analyzed by solid phase extraction or direct proteinprecipitation followed by UPLC-MS/MS. MS detection using electrospray inthe positive ion mode with monitoring of specific mass-to-chargetransitions for compound (I) using internal standards for correcting theresponse. The concentration-time data was analyzed, using standardsoftware using appropriate noncompartmental techniques to obtainestimates of the derived PK parameters.

Instrumentation Used for Analysis of Compound (I) from Dosing Compound(Ia):

Mass spectrometer (LC-MS/MS) Waters Acquity-Sciex API 5000. Analyticalcolumn Waters BEH UPLC Phenyl 100×2.1 mm column, 1.7 μm particle size.Mobile phase A: 20 mM ammonium formate (aq)+0.5% formic acid. Mobilephase B: Acetonitrile. Gradient run from 95/5% to 2/98 in 6.1 minutes.Flow rate 0.5 mL/min. MRM monitoring (multiple reaction monitoring) oftest item and the added analytical standards.

Dosing and blood sampling: Han Wistar rats were supplied by CharlesRiver Laboratories, Sulzfeld, Germany. An artificial, automaticallycontrolled, light and dark cycle of 12 hours was maintained. The ratsreceived a standard laboratory diet from Brogaarden (Altromin 1324pellets). The rats had unrestricted access to the diet. During the study(a 4-week toxicity study) the rats received once daily doses of (Ia)orally by gavage. From rats given 300 μg/kg (Ia), blood samples) from 3male satellite animals were collected on the following time points atDay 29: 0.5, 1, 2, 4, 6, 8, 12 and 24 hours after dosing.

Instrumentation Used for Analysis of Compound (I) from Dosing ofCompound (Ib):

Mass spectrometer (LC-MS/MS) Waters Acquity-Sciex API 5000. Analyticalcolumn Waters BEH UPLC Phenyl 100×2.1 mm column, 1.7 μm particle size.Mobile phase A: 20 mM ammonium formate (aq)+0.5% formic acid. Mobilephase B: Acetonitrile. Gradient run from 95/5% to 2/98 in 6.1 minutes.Flow rate 0.5 mL/min. MRM monitoring of test item and the addedanalytical standards.

Dosing and blood sampling: Han Wistar rats were supplied by CharlesRiver Laboratories, UK. An artificial, automatically controlled, lightand dark cycle of 12 hours was maintained. The rats received a standardlaboratory diet (Teklad 2014C Diet.). The rats had unrestricted accessto the diet. During the study (a 26-week toxicity study) the ratsreceived once daily doses of (Ib) orally by gavage. From rats given 300μg/kg (Ib), blood samples from 3 male satellite animals were collectedon the following time points at day 182: 0.5, 1, 2, 4, 8 and 24 hoursafter dosing.

Instrumentation Used for Analysis of Compound (I) from Dosing ofCompounds (1c) and (Id)

Mass spectrometer (LC-MS/MS) Waters Acquity—Waters Xevo TQ-S. Analyticalcolumn Acquity BEH C18 100×2.1 mm, 1.7 μm. Mobile phase A: 20 mMNH-Formate+0.2% formic acid. Mobile phase B: Acetonitrile+0.2% formicacid. Gradient run from 95/5% to 5/95% in 11.0 minutes. Flow rate 0.3mL/min. MRM monitoring of test item and the added analytical standards.

Dosing and blood sampling for compound (Id): Han Wistar rats weresupplied by Charles River Laboratories, Wiga GmbH, Germany. Anartificial, automatically controlled, light and dark cycle of 12 hourswas maintained. The rats received a standard laboratory diet fromBrogaarden (Altromin 1324 pellets). The rats had unrestricted access tothe diet. Male Han Wistar rats were dosed a single oral gavageadministration of compound (Id) orally by gavage. Rats were given 633μg/kg of compound (Id), blood samples from 3 male animals were collectedon the following time points at Day 1: 1, 2, 4, 6, 8, and 24 hours afterdosing.

Dosing and blood sampling for compound (1c): Han Wistar rats weresupplied by Envigo, UK. An artificial, automatically controlled, lightand dark cycle of 12 hours was maintained. The rats received a standardlaboratory diet Teklad 2014C. The rats had unrestricted access to thediet. Male Han Wistar rats were dosed a single oral gavageadministration of (1c). Rats were given 494 μg/kg (1c). Blood samplesfrom 3 male animals were collected on the following time points at Day1: 1, 2, 4, 6, 8, and 24 hours after dosing.

Instrumentation Used for Analysis of Apomorphine:

Mass spectrometer (UPCLC-MS/MS) Waters Acquity I-Class-Waters Xevo TQ-S.Analytical column Acquity HSS T3 C18 50×2.1 mm, 1.8 μm. Mobile phase A:10 mM NH₄—Formate 0.2% formic acid:acetonitril (95:5). Mobile phase B:10 mM NH₄—Formate 0.2% formic acid:acetonitril (5:95). Gradient run from95/5% to 5/95% in 2.40 minutes. Flow rate 0.3 mL/min. MRM detection oftest items and the added analytical standards.

Dosing and Blood Sampling for Apomorphine:

Animals for the study were as described in Example 9. Additionally, ratswere administered a single dose of apomorphine subcutaneously. From ratsadministered 3000 μg/kg (apomorphine), blood samples from 3 male animalswere collected on the following time points at Day 1: 0.25, 0.5, 1, 1.5,2, 3, 5 and 7 hours SC administration after dosing.

TABLE 3 PK parameters for(4aR,10aR)-1-Propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinoline-6,7-diol (compound (I)) after oral dosing of 0.300mg/kg compound (Ia), 0.300 mg/kg compound (Ib), 0.633 mg/kg of TFA saltof compound (Id) and 494 μg/kg compound (Ic) to Wistar rats according toExample 9 24 h T_(max) C_(max) AUC₀₋₂₄ t_(1/2) exposure compound (h)(pg/mL) (pg*h/mL) (h) (pg/mL) Prodrugs in (Ia) 1.0 3160 13600 4.09  48 ±26 the state of (Ib) 0.5 4990 31000 N/A 147 ± 28 the art (Ic) 1.0  14 104 N/A N/A Compound (Id) 4.0 1350 15500 6.8 208 ± 89 obtained by theinvention

Example 10: PK/PD of Compound (Id)/Compound (I) in Rat HyperactivityAssay Animals

In total, 206 male CD rats (Charles River, Germany) weighing 200-250grams (165-190 grams upon arrival) were used in the study. Animals werehoused at a standard temperature (22±1° C.) and in a light-controlledenvironment (lights on from 7 am to 8 μm) with ad libitum access to foodand water. The experiment described below was performed in accordancewith the standard operating procedures of Charles River DiscoveryResearch Services Finland Ltd. and in accordance with the nationalAnimal Experiment Board of Finland (Elainkoelautakunta, ELLA) authorityon animal testing.

Locomotor Activity Testing, Open Field

The test device is a square Plexiglass-arena (measuring 40×40×40 cm), inwhich the movement paths of the rats are recorded by an activity monitor(Med. Associates Inc.). Before the test period is initiated, rats arehabituated to their test cage for 60 minutes. Upon completion ofhabituation, animals were treated with either compound or vehicle andplaced back into the open field apparatus. The main test parametermeasured is ambulatory distance (recorded in 5 minute segments). Overalltime of measurement after receiving initial treatment was 360 minutes.Total follow up period in the study was 420 minutes, including 60minutes of habituation.

Results

Oral administration of compound (Id) was assessed in the rat locomotoractivity assay, and this functional readout was then correlated toplasma concentrations of compound (I). Apomorphine and pramipexole werealso concomitantly tested in this assay as comparators (i.e. knownstandard-of-care (SoC) in the Parkinson's Disease field), and plasmaconcentration was analyzed for apomorphine.

As shown in FIG. 3, compound (Id) (10 to 300 μg/kg, p.o.) increaseslocomotor activity with an effect starting approximatively 2 hours'post-administration (around the 180-minute time point) and lasting untilthe end of recording (at the 415-minute time point). In contrast, thehyperactivity induced by apomorphine (3 mg/kg, s.c.) is immediate butshort-lasting as the effect is gone 1.5 hours. post administration (atthe 150-minute time point). Pramipexole (0.3 mg/kg, s.c.) also inducesan increase in activity, but its effect appears about 1 hour postadministration and is gone 2.5 hours later (at the 270-minute timepoint). The total distance travelled as seen in FIG. 2 demonstrates asignificantly increased activity for both compound (Id) and the twocomparators tested, and this effect is the one that is to be expectedfrom dopamine agonists.

In parallel with the locomotor activity assessment, plasma samples weretaken from satellite animals at 6 different time points (1.5, 2, 3, 4, 5& 7 hour's post-dose for animals treated with compound (Id)).Pharmacokinetic analysis demonstrates that the behavioral effects ofcompound (Id) (100 μg/kg, p.o.) correlate with the plasma concentrationsof compound (I) (see FIG. 4), demonstrating that the behavioral effectof compound (Id) is driven by Compound (I) rather than by Compound (Id)itself. The corresponding exposure analysis of apomorphine (at 1.25 1.5,2, 3, 5 and 7 hours post-dose) resulted in a correlation between plasmaconcentrations of apomorphine and hyperactive behavior (see FIG. 5).

REFERENCE LIST

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1. A process for the preparation of compound (Id) with the formula below

from compound (I) with the formula below

comprising the following step reacting compound (I), or a salt thereof,with benzyl halogenide to obtain compound (A2) according to the reactionscheme below

wherein X is selected from the group consisting of Cl, Br and I.
 2. Theprocess according to claim 1, wherein: a) said benzyl halogenide isbenzyl chloride and X is Cl; or b) said benzyl halogenide is benzylbromide and X is Br.
 3. A compound of formula (A2) below:

or a salt thereof.
 4. The process according to claim 1 for thepreparation of compound (Id) with the formula below

from compound (I) with the formula below

comprising the following step subjecting compound (A2) to adebenzylation reaction to obtain compound (A3), or a salt thereofaccording to the reaction scheme below


5. A compound of formula A3 below:

or a salt thereof.
 6. The process according to claim 4, wherein thedebenzylation reaction comprises the steps of: I) reactingtrimethylsilyl iodide with compound (A2) to form a mixture; and II)adding an alcohol to said mixture from step 1) to obtain compound (A3)or a salt thereof; and III) optionally isolating compound (A3), or asalt thereof as obtained in step (II).
 7. The process according to claim6, wherein the alcohol added to said mixture in step II) is selectedfrom the group consisting of MeOH, n-heptyl alcohol, and ethanol.
 8. Theprocess according to claim 4, wherein compound (A3) is obtained in theform of a hydroiodide salt with the formula (A3-HI) below


9. The compound according to claim 5, which is in the form of ahydroiodide salt with the formula (A3-HI) below


10. The process according to claim 1 for the preparation of compound(Id) with the formula below

from compound (I) with the formula below

comprising the following step reacting compound (A3), or salt thereof,with(2S,3S,4S,5R,6R)-2-(methoxycarbonyl)-6-(2,2,2-trichloro-1-iminoethoxy)tetrahydro-2H-pyran-3,4,5-triyltriacetate to obtain compound (A4) according to the reaction schemebelow


11. The process according to claim 10, wherein compound (A3) is in theform of the hydroiodide salt (A3-HI) with the formula below:


12. A compound of formula (A4) below:

or a salt thereof.
 13. A process for the preparation of compound (Id)with the formula below

from compound (I) with the formula below

comprising the following step reacting compound (A4) withalkali-hydroxide to obtain (A5-Y) according to the reaction scheme below

wherein Y is selected from Li, Na and K.
 14. The process according toclaim 13, wherein: a) said alkali hydroxide is lithium hydroxide and Yis Li; or b) said alkali hydroxide is sodium hydroxide and Y is Na; orc) said alkali hydroxide is potassium hydroxide and Y is K.
 15. Acompound of formula A5 below:

or a salt thereof.
 16. The compound according to claim 15 which is inthe form of an alkali salt depicted below

wherein Y is selected from the group consisting of Li, Na and K.
 17. Theprocess according to claim 1 for the preparation of compound (Id) withthe formula below

from compound (I) with the formula below

comprising the following step debenzylating compound (A5-Y) to obtaincompound (Id) according to the reaction scheme below

wherein Y is selected from the group consisting of Li, Na, and K. 18.The process according to claim 1 for the preparation of compound (Id)from compound (I) comprising a step according to claim 1; followed by astep according to claim 4; followed by a step according to claim 10;followed by a step according to claim 13; followed by a step accordingto claim
 17. 19. (canceled)